Class: ActiveRecord::Base
- Inherits:
-
Object
- Object
- ActiveRecord::Base
- Defined in:
- lib/active_record/base.rb,
lib/active_record/connection_adapters/mysql_adapter.rb,
lib/active_record/connection_adapters/sqlite_adapter.rb,
lib/active_record/connection_adapters/sqlite3_adapter.rb,
lib/active_record/connection_adapters/postgresql_adapter.rb,
lib/active_record/connection_adapters/abstract/connection_specification.rb
Overview
Active Record objects don’t specify their attributes directly, but rather infer them from the table definition with which they’re linked. Adding, removing, and changing attributes and their type is done directly in the database. Any change is instantly reflected in the Active Record objects. The mapping that binds a given Active Record class to a certain database table will happen automatically in most common cases, but can be overwritten for the uncommon ones.
See the mapping rules in table_name and the full example in files/README.html for more insight.
Creation
Active Records accept constructor parameters either in a hash or as a block. The hash method is especially useful when you’re receiving the data from somewhere else, like an HTTP request. It works like this:
user = User.new(:name => "David", :occupation => "Code Artist")
user.name # => "David"
You can also use block initialization:
user = User.new do |u|
u.name = "David"
u.occupation = "Code Artist"
end
And of course you can just create a bare object and specify the attributes after the fact:
user = User.new
user.name = "David"
user.occupation = "Code Artist"
Conditions
Conditions can either be specified as a string, array, or hash representing the WHERE-part of an SQL statement. The array form is to be used when the condition input is tainted and requires sanitization. The string form can be used for statements that don’t involve tainted data. The hash form works much like the array form, except only equality and range is possible. Examples:
class User < ActiveRecord::Base
def self.authenticate_unsafely(user_name, password)
find(:first, :conditions => "user_name = '#{user_name}' AND password = '#{password}'")
end
def self.authenticate_safely(user_name, password)
find(:first, :conditions => [ "user_name = ? AND password = ?", user_name, password ])
end
def self.authenticate_safely_simply(user_name, password)
find(:first, :conditions => { :user_name => user_name, :password => password })
end
end
The authenticate_unsafely
method inserts the parameters directly into the query and is thus susceptible to SQL-injection attacks if the user_name
and password
parameters come directly from an HTTP request. The authenticate_safely
and authenticate_safely_simply
both will sanitize the user_name
and password
before inserting them in the query, which will ensure that an attacker can’t escape the query and fake the login (or worse).
When using multiple parameters in the conditions, it can easily become hard to read exactly what the fourth or fifth question mark is supposed to represent. In those cases, you can resort to named bind variables instead. That’s done by replacing the question marks with symbols and supplying a hash with values for the matching symbol keys:
Company.find(:first, :conditions => [
"id = :id AND name = :name AND division = :division AND created_at > :accounting_date",
{ :id => 3, :name => "37signals", :division => "First", :accounting_date => '2005-01-01' }
])
Similarly, a simple hash without a statement will generate conditions based on equality with the SQL AND operator. For instance:
Student.find(:all, :conditions => { :first_name => "Harvey", :status => 1 })
Student.find(:all, :conditions => params[:student])
A range may be used in the hash to use the SQL BETWEEN operator:
Student.find(:all, :conditions => { :grade => 9..12 })
An array may be used in the hash to use the SQL IN operator:
Student.find(:all, :conditions => { :grade => [9,11,12] })
Overwriting default accessors
All column values are automatically available through basic accessors on the Active Record object, but sometimes you want to specialize this behavior. This can be done by overwriting the default accessors (using the same name as the attribute) and calling read_attribute(attr_name)
and write_attribute(attr_name, value)
to actually change things. Example:
class Song < ActiveRecord::Base
# Uses an integer of seconds to hold the length of the song
def length=(minutes)
write_attribute(:length, minutes.to_i * 60)
end
def length
read_attribute(:length) / 60
end
end
You can alternatively use self[:attribute]=(value)
and self[:attribute]
instead of write_attribute(:attribute, value)
and read_attribute(:attribute)
as a shorter form.
Attribute query methods
In addition to the basic accessors, query methods are also automatically available on the Active Record object. Query methods allow you to test whether an attribute value is present.
For example, an Active Record User with the name
attribute has a name?
method that you can call to determine whether the user has a name:
user = User.new(:name => "David")
user.name? # => true
anonymous = User.new(:name => "")
anonymous.name? # => false
Accessing attributes before they have been typecasted
Sometimes you want to be able to read the raw attribute data without having the column-determined typecast run its course first. That can be done by using the <attribute>_before_type_cast
accessors that all attributes have. For example, if your Account model has a balance
attribute, you can call account.balance_before_type_cast
or account.id_before_type_cast
.
This is especially useful in validation situations where the user might supply a string for an integer field and you want to display the original string back in an error message. Accessing the attribute normally would typecast the string to 0, which isn’t what you want.
Dynamic attribute-based finders
Dynamic attribute-based finders are a cleaner way of getting (and/or creating) objects by simple queries without turning to SQL. They work by appending the name of an attribute to find_by_
or find_all_by_
, so you get finders like Person.find_by_user_name
, Person.find_all_by_last_name
, and Payment.find_by_transaction_id
. So instead of writing Person.find(:first, :conditions => ["user_name = ?", user_name])
, you just do Person.find_by_user_name(user_name)
. And instead of writing Person.find(:all, :conditions => ["last_name = ?", last_name])
, you just do Person.find_all_by_last_name(last_name)
.
It’s also possible to use multiple attributes in the same find by separating them with “and”, so you get finders like Person.find_by_user_name_and_password
or even Payment.find_by_purchaser_and_state_and_country
. So instead of writing Person.find(:first, :conditions => ["user_name = ? AND password = ?", user_name, password])
, you just do Person.find_by_user_name_and_password(user_name, password)
.
It’s even possible to use all the additional parameters to find. For example, the full interface for Payment.find_all_by_amount
is actually Payment.find_all_by_amount(amount, options)
. And the full interface to Person.find_by_user_name
is actually Person.find_by_user_name(user_name, options)
. So you could call Payment.find_all_by_amount(50, :order => "created_on")
.
The same dynamic finder style can be used to create the object if it doesn’t already exist. This dynamic finder is called with find_or_create_by_
and will return the object if it already exists and otherwise creates it, then returns it. Protected attributes won’t be set unless they are given in a block. For example:
# No 'Summer' tag exists
Tag.find_or_create_by_name("Summer") # equal to Tag.create(:name => "Summer")
# Now the 'Summer' tag does exist
Tag.find_or_create_by_name("Summer") # equal to Tag.find_by_name("Summer")
# Now 'Bob' exist and is an 'admin'
User.find_or_create_by_name('Bob', :age => 40) { |u| u.admin = true }
Use the find_or_initialize_by_
finder if you want to return a new record without saving it first. Protected attributes won’t be setted unless they are given in a block. For example:
# No 'Winter' tag exists
winter = Tag.find_or_initialize_by_name("Winter")
winter.new_record? # true
To find by a subset of the attributes to be used for instantiating a new object, pass a hash instead of a list of parameters. For example:
Tag.find_or_create_by_name(:name => "rails", :creator => current_user)
That will either find an existing tag named “rails”, or create a new one while setting the user that created it.
Saving arrays, hashes, and other non-mappable objects in text columns
Active Record can serialize any object in text columns using YAML. To do so, you must specify this with a call to the class method serialize
. This makes it possible to store arrays, hashes, and other non-mappable objects without doing any additional work. Example:
class User < ActiveRecord::Base
serialize :preferences
end
user = User.create(:preferences => { "background" => "black", "display" => large })
User.find(user.id).preferences # => { "background" => "black", "display" => large }
You can also specify a class option as the second parameter that’ll raise an exception if a serialized object is retrieved as a descendent of a class not in the hierarchy. Example:
class User < ActiveRecord::Base
serialize :preferences, Hash
end
user = User.create(:preferences => %w( one two three ))
User.find(user.id).preferences # raises SerializationTypeMismatch
Single table inheritance
Active Record allows inheritance by storing the name of the class in a column that by default is named “type” (can be changed by overwriting Base.inheritance_column
). This means that an inheritance looking like this:
class Company < ActiveRecord::Base; end
class Firm < Company; end
class Client < Company; end
class PriorityClient < Client; end
When you do Firm.create(:name => "37signals")
, this record will be saved in the companies table with type = “Firm”. You can then fetch this row again using Company.find(:first, "name = '37signals'")
and it will return a Firm object.
If you don’t have a type column defined in your table, single-table inheritance won’t be triggered. In that case, it’ll work just like normal subclasses with no special magic for differentiating between them or reloading the right type with find.
Note, all the attributes for all the cases are kept in the same table. Read more: www.martinfowler.com/eaaCatalog/singleTableInheritance.html
Connection to multiple databases in different models
Connections are usually created through ActiveRecord::Base.establish_connection and retrieved by ActiveRecord::Base.connection. All classes inheriting from ActiveRecord::Base will use this connection. But you can also set a class-specific connection. For example, if Course is an ActiveRecord::Base, but resides in a different database, you can just say Course.establish_connection
and Course and all of its subclasses will use this connection instead.
This feature is implemented by keeping a connection pool in ActiveRecord::Base that is a Hash indexed by the class. If a connection is requested, the retrieve_connection method will go up the class-hierarchy until a connection is found in the connection pool.
Exceptions
-
ActiveRecordError - Generic error class and superclass of all other errors raised by Active Record.
-
AdapterNotSpecified - The configuration hash used in
establish_connection
didn’t include an:adapter
key. -
AdapterNotFound - The
:adapter
key used inestablish_connection
specified a non-existent adapter (or a bad spelling of an existing one). -
AssociationTypeMismatch - The object assigned to the association wasn’t of the type specified in the association definition.
-
SerializationTypeMismatch - The serialized object wasn’t of the class specified as the second parameter.
-
ConnectionNotEstablished+ - No connection has been established. Use
establish_connection
before querying. -
RecordNotFound - No record responded to the
find
method. Either the row with the given ID doesn’t exist or the row didn’t meet the additional restrictions. Somefind
calls do not raise this exception to signal nothing was found, please check its documentation for further details. -
StatementInvalid - The database server rejected the SQL statement. The precise error is added in the message.
-
MultiparameterAssignmentErrors - Collection of errors that occurred during a mass assignment using the
attributes=
method. Theerrors
property of this exception contains an array of AttributeAssignmentError objects that should be inspected to determine which attributes triggered the errors. -
AttributeAssignmentError - An error occurred while doing a mass assignment through the
attributes=
method. You can inspect theattribute
property of the exception object to determine which attribute triggered the error.
Note: The attributes listed are class-level attributes (accessible from both the class and instance level). So it’s possible to assign a logger to the class through Base.logger=
which will then be used by all instances in the current object space.
Defined Under Namespace
Classes: ConnectionSpecification
Constant Summary collapse
- @@subclasses =
{}
- @@configurations =
{}
- @@primary_key_prefix_type =
nil
- @@table_name_prefix =
""
- @@table_name_suffix =
""
- @@pluralize_table_names =
true
- @@colorize_logging =
true
- @@default_timezone =
:local
- @@allow_concurrency =
false
- @@schema_format =
:ruby
- @@timestamped_migrations =
true
- @@verification_timeout =
0
- @@defined_connections =
The class -> [adapter_method, config] map
{}
- @@active_connections =
The class -> thread id -> adapter cache. (class -> adapter if not allow_concurrency)
{}
Class Attribute Summary collapse
-
.abstract_class ⇒ Object
Set this to true if this is an abstract class (see
abstract_class?
).
Class Method Summary collapse
-
.===(object) ⇒ Object
Overwrite the default class equality method to provide support for association proxies.
-
.abstract_class? ⇒ Boolean
Returns whether this class is a base AR class.
-
.accessible_attributes ⇒ Object
Returns an array of all the attributes that have been made accessible to mass-assignment.
-
.active_connection_name ⇒ Object
:nodoc:.
-
.all(*args) ⇒ Object
This is an alias for find(:all).
-
.allow_concurrency=(threaded) ⇒ Object
set concurrency support flag (not thread safe, like most of the methods in this file).
-
.attr_accessible(*attributes) ⇒ Object
Specifies a white list of model attributes that can be set via mass-assignment, such as
new(attributes)
,update_attributes(attributes)
, orattributes=(attributes)
. -
.attr_protected(*attributes) ⇒ Object
Attributes named in this macro are protected from mass-assignment, such as
new(attributes)
,update_attributes(attributes)
, orattributes=(attributes)
. -
.attr_readonly(*attributes) ⇒ Object
Attributes listed as readonly can be set for a new record, but will be ignored in database updates afterwards.
-
.base_class ⇒ Object
Returns the base AR subclass that this class descends from.
-
.benchmark(title, log_level = Logger::DEBUG, use_silence = true) ⇒ Object
Log and benchmark multiple statements in a single block.
-
.class_name(table_name = table_name) ⇒ Object
Turns the
table_name
back into a class name following the reverse rules oftable_name
. -
.clear_active_connection_name ⇒ Object
:nodoc:.
-
.clear_active_connections! ⇒ Object
Clears the cache which maps classes to connections.
-
.clear_reloadable_connections! ⇒ Object
Clears the cache which maps classes.
-
.column_methods_hash ⇒ Object
Returns a hash of all the methods added to query each of the columns in the table with the name of the method as the key and true as the value.
-
.column_names ⇒ Object
Returns an array of column names as strings.
-
.columns ⇒ Object
Returns an array of column objects for the table associated with this class.
-
.columns_hash ⇒ Object
Returns a hash of column objects for the table associated with this class.
-
.connected? ⇒ Boolean
Returns true if a connection that’s accessible to this class has already been opened.
-
.connection ⇒ Object
Returns the connection currently associated with the class.
-
.connection=(spec) ⇒ Object
Set the connection for the class.
-
.content_columns ⇒ Object
Returns an array of column objects where the primary id, all columns ending in “_id” or “_count”, and columns used for single table inheritance have been removed.
-
.count_by_sql(sql) ⇒ Object
Returns the result of an SQL statement that should only include a COUNT(*) in the SELECT part.
-
.create(attributes = nil, &block) ⇒ Object
Creates an object (or multiple objects) and saves it to the database, if validations pass.
-
.decrement_counter(counter_name, id) ⇒ Object
Decrement a number field by one, usually representing a count.
-
.delete(id) ⇒ Object
Delete an object (or multiple objects) where the
id
given matches the primary_key. -
.delete_all(conditions = nil) ⇒ Object
Deletes the records matching
conditions
without instantiating the records first, and hence not calling the destroy method and invoking callbacks. -
.descends_from_active_record? ⇒ Boolean
True if this isn’t a concrete subclass needing a STI type condition.
-
.destroy(id) ⇒ Object
Destroy an object (or multiple objects) that has the given id, the object is instantiated first, therefore all callbacks and filters are fired off before the object is deleted.
-
.destroy_all(conditions = nil) ⇒ Object
Destroys the records matching
conditions
by instantiating each record and calling the destroy method. -
.establish_connection(spec = nil) ⇒ Object
Establishes the connection to the database.
-
.exists?(id_or_conditions) ⇒ Boolean
Checks whether a record exists in the database that matches conditions given.
-
.find(*args) ⇒ Object
Find operates with four different retrieval approaches:.
-
.find_by_sql(sql) ⇒ Object
Executes a custom SQL query against your database and returns all the results.
-
.finder_needs_type_condition? ⇒ Boolean
:nodoc:.
-
.first(*args) ⇒ Object
A convenience wrapper for
find(:first, *args)
. -
.get_primary_key(base_name) ⇒ Object
:nodoc:.
-
.human_attribute_name(attribute_key_name) ⇒ Object
Transforms attribute key names into a more humane format, such as “First name” instead of “first_name”.
-
.increment_counter(counter_name, id) ⇒ Object
Increment a number field by one, usually representing a count.
-
.inheritance_column ⇒ Object
Defines the column name for use with single table inheritance – can be set in subclasses like so: self.inheritance_column = “type_id”.
-
.inherited(child) ⇒ Object
:nodoc:.
-
.inspect ⇒ Object
Returns a string like ‘Post id:integer, title:string, body:text’.
-
.last(*args) ⇒ Object
A convenience wrapper for
find(:last, *args)
. -
.log_connections ⇒ Object
connection state logging.
-
.mysql_connection(config) ⇒ Object
Establishes a connection to the database that’s used by all Active Record objects.
-
.postgresql_connection(config) ⇒ Object
Establishes a connection to the database that’s used by all Active Record objects.
-
.primary_key ⇒ Object
Defines the primary key field – can be overridden in subclasses.
-
.protected_attributes ⇒ Object
Returns an array of all the attributes that have been protected from mass-assignment.
-
.quote_value(value, column = nil) ⇒ Object
:nodoc:.
-
.readonly_attributes ⇒ Object
Returns an array of all the attributes that have been specified as readonly.
-
.remove_connection(klass = self) ⇒ Object
Remove the connection for this class.
- .require_mysql ⇒ Object
-
.reset_column_information ⇒ Object
Resets all the cached information about columns, which will cause them to be reloaded on the next request.
-
.reset_column_information_and_inheritable_attributes_for_all_subclasses ⇒ Object
:nodoc:.
-
.reset_primary_key ⇒ Object
:nodoc:.
-
.reset_sequence_name ⇒ Object
:nodoc:.
-
.reset_subclasses ⇒ Object
:nodoc:.
-
.reset_table_name ⇒ Object
:nodoc:.
- .respond_to?(method_id, include_private = false) ⇒ Boolean
-
.retrieve_connection ⇒ Object
Locate the connection of the nearest super class.
-
.sanitize(object) ⇒ Object
Used to sanitize objects before they’re used in an SQL SELECT statement.
-
.sequence_name ⇒ Object
Lazy-set the sequence name to the connection’s default.
-
.serialize(attr_name, class_name = Object) ⇒ Object
If you have an attribute that needs to be saved to the database as an object, and retrieved as the same object, then specify the name of that attribute using this method and it will be handled automatically.
-
.serialized_attributes ⇒ Object
Returns a hash of all the attributes that have been specified for serialization as keys and their class restriction as values.
-
.set_inheritance_column(value = nil, &block) ⇒ Object
(also: inheritance_column=)
Sets the name of the inheritance column to use to the given value, or (if the value # is nil or false) to the value returned by the given block.
-
.set_primary_key(value = nil, &block) ⇒ Object
(also: primary_key=)
Sets the name of the primary key column to use to the given value, or (if the value is nil or false) to the value returned by the given block.
-
.set_sequence_name(value = nil, &block) ⇒ Object
(also: sequence_name=)
Sets the name of the sequence to use when generating ids to the given value, or (if the value is nil or false) to the value returned by the given block.
-
.set_table_name(value = nil, &block) ⇒ Object
(also: table_name=)
Sets the table name to use to the given value, or (if the value is nil or false) to the value returned by the given block.
-
.silence ⇒ Object
Silences the logger for the duration of the block.
-
.single_threaded_active_connections ⇒ Object
:nodoc:.
-
.sqlite3_connection(config) ⇒ Object
sqlite3 adapter reuses sqlite_connection.
-
.sqlite_connection(config) ⇒ Object
Establishes a connection to the database that’s used by all Active Record objects.
- .sti_name ⇒ Object
-
.table_exists? ⇒ Boolean
Indicates whether the table associated with this class exists.
-
.table_name ⇒ Object
Guesses the table name (in forced lower-case) based on the name of the class in the inheritance hierarchy descending directly from ActiveRecord::Base.
-
.thread_safe_active_connections ⇒ Object
Retrieve the connection cache.
-
.update(id, attributes) ⇒ Object
Updates an object (or multiple objects) and saves it to the database, if validations pass.
-
.update_all(updates, conditions = nil, options = {}) ⇒ Object
Updates all records with details given if they match a set of conditions supplied, limits and order can also be supplied.
-
.update_counters(id, counters) ⇒ Object
A generic “counter updater” implementation, intended primarily to be used by increment_counter and decrement_counter, but which may also be useful on its own.
-
.verify_active_connections! ⇒ Object
Verify active connections.
Instance Method Summary collapse
-
#==(comparison_object) ⇒ Object
Returns true if the
comparison_object
is the same object, or is of the same type and has the same id. -
#[](attr_name) ⇒ Object
Returns the value of the attribute identified by
attr_name
after it has been typecast (for example, “2004-12-12” in a data column is cast to a date object, like Date.new(2004, 12, 12)). -
#[]=(attr_name, value) ⇒ Object
Updates the attribute identified by
attr_name
with the specifiedvalue
. -
#attribute_for_inspect(attr_name) ⇒ Object
Format attributes nicely for inspect.
-
#attribute_names ⇒ Object
Returns an array of names for the attributes available on this object sorted alphabetically.
-
#attribute_present?(attribute) ⇒ Boolean
Returns true if the specified
attribute
has been set by the user or by a database load and is neither nil nor empty? (the latter only applies to objects that respond to empty?, most notably Strings). -
#attributes ⇒ Object
Returns a hash of all the attributes with their names as keys and the values of the attributes as values.
-
#attributes=(new_attributes, guard_protected_attributes = true) ⇒ Object
Allows you to set all the attributes at once by passing in a hash with keys matching the attribute names (which again matches the column names).
-
#attributes_before_type_cast ⇒ Object
Returns a hash of attributes before typecasting and deserialization.
-
#becomes(klass) ⇒ Object
Returns an instance of the specified
klass
with the attributes of the current record. -
#cache_key ⇒ Object
Returns a cache key that can be used to identify this record.
-
#clone ⇒ Object
Returns a clone of the record that hasn’t been assigned an id yet and is treated as a new record.
-
#column_for_attribute(name) ⇒ Object
Returns the column object for the named attribute.
-
#connection ⇒ Object
Returns the connection currently associated with the class.
-
#decrement(attribute, by = 1) ⇒ Object
Initializes
attribute
to zero ifnil
and subtracts the value passed asby
(default is 1). -
#decrement!(attribute, by = 1) ⇒ Object
Wrapper around
decrement
that saves the record. -
#destroy ⇒ Object
Deletes the record in the database and freezes this instance to reflect that no changes should be made (since they can’t be persisted).
-
#eql?(comparison_object) ⇒ Boolean
Delegates to ==.
-
#freeze ⇒ Object
Freeze the attributes hash such that associations are still accessible, even on destroyed records.
-
#frozen? ⇒ Boolean
Returns
true
if the attributes hash has been frozen. -
#has_attribute?(attr_name) ⇒ Boolean
Returns true if the given attribute is in the attributes hash.
-
#hash ⇒ Object
Delegates to id in order to allow two records of the same type and id to work with something like: [ Person.find(1), Person.find(2), Person.find(3) ] & [ Person.find(1), Person.find(4) ] # => [ Person.find(1) ].
-
#id ⇒ Object
A model instance’s primary key is always available as model.id whether you name it the default ‘id’ or set it to something else.
-
#id=(value) ⇒ Object
Sets the primary ID.
-
#id_before_type_cast ⇒ Object
:nodoc:.
-
#increment(attribute, by = 1) ⇒ Object
Initializes
attribute
to zero ifnil
and adds the value passed asby
(default is 1). -
#increment!(attribute, by = 1) ⇒ Object
Wrapper around
increment
that saves the record. -
#initialize(attributes = nil) ⇒ Base
constructor
New objects can be instantiated as either empty (pass no construction parameter) or pre-set with attributes but not yet saved (pass a hash with key names matching the associated table column names).
-
#inspect ⇒ Object
Returns the contents of the record as a nicely formatted string.
-
#new_record? ⇒ Boolean
Returns true if this object hasn’t been saved yet – that is, a record for the object doesn’t exist yet.
-
#quoted_id ⇒ Object
:nodoc:.
-
#readonly! ⇒ Object
Marks this record as read only.
-
#readonly? ⇒ Boolean
Returns
true
if the record is read only. -
#reload(options = nil) ⇒ Object
Reloads the attributes of this object from the database.
-
#save ⇒ Object
-
No record exists: Creates a new record with values matching those of the object attributes.
-
-
#save! ⇒ Object
Attempts to save the record, but instead of just returning false if it couldn’t happen, it raises a RecordNotSaved exception.
-
#to_param ⇒ Object
Enables Active Record objects to be used as URL parameters in Action Pack automatically.
-
#toggle(attribute) ⇒ Object
Assigns to
attribute
the boolean opposite ofattribute?
. -
#toggle!(attribute) ⇒ Object
Wrapper around
toggle
that saves the record. -
#update_attribute(name, value) ⇒ Object
Updates a single attribute and saves the record.
-
#update_attributes(attributes) ⇒ Object
Updates all the attributes from the passed-in Hash and saves the record.
-
#update_attributes!(attributes) ⇒ Object
Updates an object just like Base.update_attributes but calls save! instead of save so an exception is raised if the record is invalid.
Constructor Details
#initialize(attributes = nil) ⇒ Base
New objects can be instantiated as either empty (pass no construction parameter) or pre-set with attributes but not yet saved (pass a hash with key names matching the associated table column names). In both instances, valid attribute keys are determined by the column names of the associated table – hence you can’t have attributes that aren’t part of the table columns.
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# File 'lib/active_record/base.rb', line 2136 def initialize(attributes = nil) @attributes = attributes_from_column_definition @attributes_cache = {} @new_record = true ensure_proper_type self.attributes = attributes unless attributes.nil? self.class.send(:scope, :create).each { |att,value| self.send("#{att}=", value) } if self.class.send(:scoped?, :create) result = yield self if block_given? callback(:after_initialize) if respond_to_without_attributes?(:after_initialize) result end |
Class Attribute Details
.abstract_class ⇒ Object
Set this to true if this is an abstract class (see abstract_class?
).
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# File 'lib/active_record/base.rb', line 1285 def abstract_class @abstract_class end |
Class Method Details
.===(object) ⇒ Object
Overwrite the default class equality method to provide support for association proxies.
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# File 'lib/active_record/base.rb', line 1273 def ===(object) object.is_a?(self) end |
.abstract_class? ⇒ Boolean
Returns whether this class is a base AR class. If A is a base class and B descends from A, then B.base_class will return B.
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# File 'lib/active_record/base.rb', line 1289 def abstract_class? defined?(@abstract_class) && @abstract_class == true end |
.accessible_attributes ⇒ Object
Returns an array of all the attributes that have been made accessible to mass-assignment.
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# File 'lib/active_record/base.rb', line 939 def accessible_attributes # :nodoc: read_inheritable_attribute("attr_accessible") end |
.active_connection_name ⇒ Object
:nodoc:
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# File 'lib/active_record/connection_adapters/abstract/connection_specification.rb', line 54 def active_connection_name #:nodoc: @active_connection_name ||= if active_connections[name] || @@defined_connections[name] name elsif self == ActiveRecord::Base nil else superclass.active_connection_name end end |
.all(*args) ⇒ Object
This is an alias for find(:all). You can pass in all the same arguments to this method as you can to find(:all)
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# File 'lib/active_record/base.rb', line 559 def all(*args) find(:all, *args) end |
.allow_concurrency=(threaded) ⇒ Object
set concurrency support flag (not thread safe, like most of the methods in this file)
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# File 'lib/active_record/connection_adapters/abstract/connection_specification.rb', line 41 def allow_concurrency=(threaded) #:nodoc: logger.debug "allow_concurrency=#{threaded}" if logger return if @@allow_concurrency == threaded clear_all_cached_connections! @@allow_concurrency = threaded method_prefix = threaded ? "thread_safe" : "single_threaded" sing = (class << self; self; end) [:active_connections, :scoped_methods].each do |method| sing.send(:alias_method, method, "#{method_prefix}_#{method}") end log_connections if logger end |
.attr_accessible(*attributes) ⇒ Object
Specifies a white list of model attributes that can be set via mass-assignment, such as new(attributes)
, update_attributes(attributes)
, or attributes=(attributes)
This is the opposite of the attr_protected
macro: Mass-assignment will only set attributes in this list, to assign to the rest of attributes you can use direct writer methods. This is meant to protect sensitive attributes from being overwritten by malicious users tampering with URLs or forms. If you’d rather start from an all-open default and restrict attributes as needed, have a look at attr_protected
.
class Customer < ActiveRecord::Base
attr_accessible :name, :nickname
end
customer = Customer.new(:name => "David", :nickname => "Dave", :credit_rating => "Excellent")
customer. # => nil
customer.attributes = { :name => "Jolly fellow", :credit_rating => "Superb" }
customer. # => nil
customer. = "Average"
customer. # => "Average"
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# File 'lib/active_record/base.rb', line 934 def attr_accessible(*attributes) write_inheritable_attribute("attr_accessible", Set.new(attributes.map(&:to_s)) + (accessible_attributes || [])) end |
.attr_protected(*attributes) ⇒ Object
Attributes named in this macro are protected from mass-assignment, such as new(attributes)
, update_attributes(attributes)
, or attributes=(attributes)
.
Mass-assignment to these attributes will simply be ignored, to assign to them you can use direct writer methods. This is meant to protect sensitive attributes from being overwritten by malicious users tampering with URLs or forms.
class Customer < ActiveRecord::Base
attr_protected :credit_rating
end
customer = Customer.new("name" => David, "credit_rating" => "Excellent")
customer. # => nil
customer.attributes = { "description" => "Jolly fellow", "credit_rating" => "Superb" }
customer. # => nil
customer. = "Average"
customer. # => "Average"
To start from an all-closed default and enable attributes as needed, have a look at attr_accessible
.
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# File 'lib/active_record/base.rb', line 901 def attr_protected(*attributes) write_inheritable_attribute("attr_protected", Set.new(attributes.map(&:to_s)) + (protected_attributes || [])) end |
.attr_readonly(*attributes) ⇒ Object
Attributes listed as readonly can be set for a new record, but will be ignored in database updates afterwards.
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# File 'lib/active_record/base.rb', line 944 def attr_readonly(*attributes) write_inheritable_attribute("attr_readonly", Set.new(attributes.map(&:to_s)) + (readonly_attributes || [])) end |
.base_class ⇒ Object
Returns the base AR subclass that this class descends from. If A extends AR::Base, A.base_class will return A. If B descends from A through some arbitrarily deep hierarchy, B.base_class will return A.
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# File 'lib/active_record/base.rb', line 1280 def base_class class_of_active_record_descendant(self) end |
.benchmark(title, log_level = Logger::DEBUG, use_silence = true) ⇒ Object
Log and benchmark multiple statements in a single block. Example:
Project.benchmark("Creating project") do
project = Project.create("name" => "stuff")
project.create_manager("name" => "David")
project.milestones << Milestone.find(:all)
end
The benchmark is only recorded if the current level of the logger is less than or equal to the log_level
, which makes it easy to include benchmarking statements in production software that will remain inexpensive because the benchmark will only be conducted if the log level is low enough.
The logging of the multiple statements is turned off unless use_silence
is set to false.
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# File 'lib/active_record/base.rb', line 1253 def benchmark(title, log_level = Logger::DEBUG, use_silence = true) if logger && logger.level <= log_level result = nil seconds = Benchmark.realtime { result = use_silence ? silence { yield } : yield } logger.add(log_level, "#{title} (#{'%.5f' % seconds})") result else yield end end |
.class_name(table_name = table_name) ⇒ Object
Turns the table_name
back into a class name following the reverse rules of table_name
.
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# File 'lib/active_record/base.rb', line 1134 def class_name(table_name = table_name) # :nodoc: # remove any prefix and/or suffix from the table name class_name = table_name[table_name_prefix.length..-(table_name_suffix.length + 1)].camelize class_name = class_name.singularize if pluralize_table_names class_name end |
.clear_active_connection_name ⇒ Object
:nodoc:
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# File 'lib/active_record/connection_adapters/abstract/connection_specification.rb', line 65 def clear_active_connection_name #:nodoc: @active_connection_name = nil subclasses.each { |klass| klass.clear_active_connection_name } end |
.clear_active_connections! ⇒ Object
Clears the cache which maps classes to connections.
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# File 'lib/active_record/connection_adapters/abstract/connection_specification.rb', line 84 def clear_active_connections! clear_cache!(@@active_connections) do |name, conn| conn.disconnect! end end |
.clear_reloadable_connections! ⇒ Object
Clears the cache which maps classes
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# File 'lib/active_record/connection_adapters/abstract/connection_specification.rb', line 91 def clear_reloadable_connections! if @@allow_concurrency # With concurrent connections @@active_connections is # a hash keyed by thread id. @@active_connections.each do |thread_id, conns| conns.each do |name, conn| if conn.requires_reloading? conn.disconnect! @@active_connections[thread_id].delete(name) end end end else @@active_connections.each do |name, conn| if conn.requires_reloading? conn.disconnect! @@active_connections.delete(name) end end end end |
.column_methods_hash ⇒ Object
Returns a hash of all the methods added to query each of the columns in the table with the name of the method as the key and true as the value. This makes it possible to do O(1) lookups in respond_to? to check if a given method for attribute is available.
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# File 'lib/active_record/base.rb', line 1174 def column_methods_hash #:nodoc: @dynamic_methods_hash ||= column_names.inject(Hash.new(false)) do |methods, attr| attr_name = attr.to_s methods[attr.to_sym] = attr_name methods["#{attr}=".to_sym] = attr_name methods["#{attr}?".to_sym] = attr_name methods["#{attr}_before_type_cast".to_sym] = attr_name methods end end |
.column_names ⇒ Object
Returns an array of column names as strings.
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# File 'lib/active_record/base.rb', line 1161 def column_names @column_names ||= columns.map { |column| column.name } end |
.columns ⇒ Object
Returns an array of column objects for the table associated with this class.
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# File 'lib/active_record/base.rb', line 1147 def columns unless defined?(@columns) && @columns @columns = connection.columns(table_name, "#{name} Columns") @columns.each { |column| column.primary = column.name == primary_key } end @columns end |
.columns_hash ⇒ Object
Returns a hash of column objects for the table associated with this class.
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# File 'lib/active_record/base.rb', line 1156 def columns_hash @columns_hash ||= columns.inject({}) { |hash, column| hash[column.name] = column; hash } end |
.connected? ⇒ Boolean
Returns true if a connection that’s accessible to this class has already been opened.
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# File 'lib/active_record/connection_adapters/abstract/connection_specification.rb', line 269 def self.connected? active_connections[active_connection_name] ? true : false end |
.connection ⇒ Object
Returns the connection currently associated with the class. This can also be used to “borrow” the connection to do database work unrelated to any of the specific Active Records.
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# File 'lib/active_record/connection_adapters/abstract/connection_specification.rb', line 73 def connection if defined?(@active_connection_name) && (conn = active_connections[@active_connection_name]) conn else # retrieve_connection sets the cache key. conn = retrieve_connection active_connections[@active_connection_name] = conn end end |
.connection=(spec) ⇒ Object
Set the connection for the class.
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# File 'lib/active_record/connection_adapters/abstract/connection_specification.rb', line 287 def self.connection=(spec) #:nodoc: if spec.kind_of?(ActiveRecord::ConnectionAdapters::AbstractAdapter) active_connections[name] = spec elsif spec.kind_of?(ConnectionSpecification) config = spec.config.reverse_merge(:allow_concurrency => @@allow_concurrency) self.connection = self.send(spec.adapter_method, config) elsif spec.nil? raise ConnectionNotEstablished else establish_connection spec end end |
.content_columns ⇒ Object
Returns an array of column objects where the primary id, all columns ending in “_id” or “_count”, and columns used for single table inheritance have been removed.
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# File 'lib/active_record/base.rb', line 1167 def content_columns @content_columns ||= columns.reject { |c| c.primary || c.name =~ /(_id|_count)$/ || c.name == inheritance_column } end |
.count_by_sql(sql) ⇒ Object
Returns the result of an SQL statement that should only include a COUNT(*) in the SELECT part. The use of this method should be restricted to complicated SQL queries that can’t be executed using the ActiveRecord::Calculations class methods. Look into those before using this.
Attributes
-
sql
- An SQL statement which should return a count query from the database, see the example below.
Examples
Product.count_by_sql "SELECT COUNT(*) FROM sales s, customers c WHERE s.customer_id = c.id"
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# File 'lib/active_record/base.rb', line 805 def count_by_sql(sql) sql = sanitize_conditions(sql) connection.select_value(sql, "#{name} Count").to_i end |
.create(attributes = nil, &block) ⇒ Object
Creates an object (or multiple objects) and saves it to the database, if validations pass. The resulting object is returned whether the object was saved successfully to the database or not.
The attributes
parameter can be either be a Hash or an Array of Hashes. These Hashes describe the attributes on the objects that are to be created.
Examples
# Create a single new object
User.create(:first_name => 'Jamie')
# Create an Array of new objects
User.create([{ :first_name => 'Jamie' }, { :first_name => 'Jeremy' }])
# Create a single object and pass it into a block to set other attributes.
User.create(:first_name => 'Jamie') do |u|
u.is_admin = false
end
# Creating an Array of new objects using a block, where the block is executed for each object:
User.create([{ :first_name => 'Jamie' }, { :first_name => 'Jeremy' }]) do |u|
u.is_admin = false
end
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# File 'lib/active_record/base.rb', line 638 def create(attributes = nil, &block) if attributes.is_a?(Array) attributes.collect { |attr| create(attr, &block) } else object = new(attributes) yield(object) if block_given? object.save object end end |
.decrement_counter(counter_name, id) ⇒ Object
Decrement a number field by one, usually representing a count.
This works the same as increment_counter but reduces the column value by 1 instead of increasing it.
Attributes
-
counter_name
- The name of the field that should be decremented. -
id
- The id of the object that should be decremented.
Examples
# Decrement the post_count column for the record with an id of 5
DiscussionBoard.decrement_counter(:post_count, 5)
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# File 'lib/active_record/base.rb', line 872 def decrement_counter(counter_name, id) update_counters(id, counter_name => -1) end |
.delete(id) ⇒ Object
Delete an object (or multiple objects) where the id
given matches the primary_key. A SQL DELETE
command is executed on the database which means that no callbacks are fired off running this. This is an efficient method of deleting records that don’t need cleaning up after or other actions to be taken.
Objects are not instantiated with this method.
Attributes
-
id
- Can be either an Integer or an Array of Integers.
Examples
# Delete a single object
Todo.delete(1)
# Delete multiple objects
todos = [1,2,3]
Todo.delete(todos)
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# File 'lib/active_record/base.rb', line 694 def delete(id) delete_all([ "#{connection.quote_column_name(primary_key)} IN (?)", id ]) end |
.delete_all(conditions = nil) ⇒ Object
Deletes the records matching conditions
without instantiating the records first, and hence not calling the destroy method and invoking callbacks. This is a single SQL query, much more efficient than destroy_all.
Attributes
-
conditions
- Conditions are specified the same way as withfind
method.
Example
Post.delete_all "person_id = 5 AND (category = 'Something' OR category = 'Else')"
This deletes the affected posts all at once with a single DELETE query. If you need to destroy dependent associations or call your before_ or after_destroy callbacks, use the destroy_all
method instead.
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# File 'lib/active_record/base.rb', line 788 def delete_all(conditions = nil) sql = "DELETE FROM #{quoted_table_name} " add_conditions!(sql, conditions, scope(:find)) connection.delete(sql, "#{name} Delete all") end |
.descends_from_active_record? ⇒ Boolean
True if this isn’t a concrete subclass needing a STI type condition.
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# File 'lib/active_record/base.rb', line 1203 def descends_from_active_record? if superclass.abstract_class? superclass.descends_from_active_record? else superclass == Base || !columns_hash.include?(inheritance_column) end end |
.destroy(id) ⇒ Object
Destroy an object (or multiple objects) that has the given id, the object is instantiated first, therefore all callbacks and filters are fired off before the object is deleted. This method is less efficient than ActiveRecord#delete but allows cleanup methods and other actions to be run.
This essentially finds the object (or multiple objects) with the given id, creates a new object from the attributes, and then calls destroy on it.
Attributes
-
id
- Can be either an Integer or an Array of Integers.
Examples
# Destroy a single object
Todo.destroy(1)
# Destroy multiple objects
todos = [1,2,3]
Todo.destroy(todos)
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# File 'lib/active_record/base.rb', line 717 def destroy(id) if id.is_a?(Array) id.map { |one_id| destroy(one_id) } else find(id).destroy end end |
.destroy_all(conditions = nil) ⇒ Object
Destroys the records matching conditions
by instantiating each record and calling the destroy method. This means at least 2*N database queries to destroy N records, so avoid destroy_all if you are deleting many records. If you want to simply delete records without worrying about dependent associations or callbacks, use the much faster delete_all
method instead.
Attributes
-
conditions
- Conditions are specified the same way as withfind
method.
Example
Person.destroy_all "last_login < '2004-04-04'"
This loads and destroys each person one by one, including its dependent associations and before_ and after_destroy callbacks.
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# File 'lib/active_record/base.rb', line 770 def destroy_all(conditions = nil) find(:all, :conditions => conditions).each { |object| object.destroy } end |
.establish_connection(spec = nil) ⇒ Object
Establishes the connection to the database. Accepts a hash as input where the :adapter
key must be specified with the name of a database adapter (in lower-case) example for regular databases (MySQL, Postgresql, etc):
ActiveRecord::Base.establish_connection(
:adapter => "mysql",
:host => "localhost",
:username => "myuser",
:password => "mypass",
:database => "somedatabase"
)
Example for SQLite database:
ActiveRecord::Base.establish_connection(
:adapter => "sqlite",
:database => "path/to/dbfile"
)
Also accepts keys as strings (for parsing from YAML for example):
ActiveRecord::Base.establish_connection(
"adapter" => "sqlite",
"database" => "path/to/dbfile"
)
The exceptions AdapterNotSpecified, AdapterNotFound and ArgumentError may be returned on an error.
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# File 'lib/active_record/connection_adapters/abstract/connection_specification.rb', line 205 def self.establish_connection(spec = nil) case spec when nil raise AdapterNotSpecified unless defined? RAILS_ENV establish_connection(RAILS_ENV) when ConnectionSpecification clear_active_connection_name @active_connection_name = name @@defined_connections[name] = spec when Symbol, String if configuration = configurations[spec.to_s] establish_connection(configuration) else raise AdapterNotSpecified, "#{spec} database is not configured" end else spec = spec.symbolize_keys unless spec.key?(:adapter) then raise AdapterNotSpecified, "database configuration does not specify adapter" end begin require 'rubygems' gem "activerecord-#{spec[:adapter]}-adapter" require "active_record/connection_adapters/#{spec[:adapter]}_adapter" rescue LoadError begin require "active_record/connection_adapters/#{spec[:adapter]}_adapter" rescue LoadError raise "Please install the #{spec[:adapter]} adapter: `gem install activerecord-#{spec[:adapter]}-adapter` (#{$!})" end end adapter_method = "#{spec[:adapter]}_connection" if !respond_to?(adapter_method) raise AdapterNotFound, "database configuration specifies nonexistent #{spec[:adapter]} adapter" end remove_connection establish_connection(ConnectionSpecification.new(spec, adapter_method)) end end |
.exists?(id_or_conditions) ⇒ Boolean
Checks whether a record exists in the database that matches conditions given. These conditions can either be a single integer representing a primary key id to be found, or a condition to be matched like using ActiveRecord#find.
The id_or_conditions
parameter can be an Integer or a String if you want to search the primary key column of the table for a matching id, or if you’re looking to match against a condition you can use an Array or a Hash.
Possible gotcha: You can’t pass in a condition as a string e.g. “name = ‘Jamie’”, this would be sanitized and then queried against the primary key column as “id = ‘name = 'Jamie”
Examples
Person.exists?(5)
Person.exists?('5')
Person.exists?(:name => "David")
Person.exists?(['name LIKE ?', "%#{query}%"])
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# File 'lib/active_record/base.rb', line 605 def exists?(id_or_conditions) connection.select_all( construct_finder_sql( :select => "#{quoted_table_name}.#{primary_key}", :conditions => (id_or_conditions), :limit => 1 ), "#{name} Exists" ).size > 0 end |
.find(*args) ⇒ Object
Find operates with four different retrieval approaches:
-
Find by id - This can either be a specific id (1), a list of ids (1, 5, 6), or an array of ids ([5, 6, 10]). If no record can be found for all of the listed ids, then RecordNotFound will be raised.
-
Find first - This will return the first record matched by the options used. These options can either be specific conditions or merely an order. If no record can be matched,
nil
is returned. UseModel.find(:first, *args)
or its shortcutModel.first(*args)
. -
Find last - This will return the last record matched by the options used. These options can either be specific conditions or merely an order. If no record can be matched,
nil
is returned. UseModel.find(:last, *args)
or its shortcutModel.last(*args)
. -
Find all - This will return all the records matched by the options used. If no records are found, an empty array is returned. Use
Model.find(:all, *args)
or its shortcutModel.all(*args)
.
All approaches accept an options hash as their last parameter.
Attributes
-
:conditions
- An SQL fragment like “administrator = 1” or[ "user_name = ?", username ]
. See conditions in the intro. -
:order
- An SQL fragment like “created_at DESC, name”. -
:group
- An attribute name by which the result should be grouped. Uses theGROUP BY
SQL-clause. -
:limit
- An integer determining the limit on the number of rows that should be returned. -
:offset
- An integer determining the offset from where the rows should be fetched. So at 5, it would skip rows 0 through 4. -
:joins
- Either an SQL fragment for additional joins like “LEFT JOIN comments ON comments.post_id = id” (rarely needed) or named associations in the same form used for the:include
option, which will perform anINNER JOIN
on the associated table(s). If the value is a string, then the records will be returned read-only since they will have attributes that do not correspond to the table’s columns. Pass:readonly => false
to override. -
:include
- Names associations that should be loaded alongside. The symbols named refer to already defined associations. See eager loading under Associations. -
:select
- By default, this is “*” as in “SELECT * FROM”, but can be changed if you, for example, want to do a join but not include the joined columns. -
:from
- By default, this is the table name of the class, but can be changed to an alternate table name (or even the name of a database view). -
:readonly
- Mark the returned records read-only so they cannot be saved or updated. -
:lock
- An SQL fragment like “FOR UPDATE” or “LOCK IN SHARE MODE”.:lock => true
gives connection’s default exclusive lock, usually “FOR UPDATE”.
Examples
# find by id
Person.find(1) # returns the object for ID = 1
Person.find(1, 2, 6) # returns an array for objects with IDs in (1, 2, 6)
Person.find([7, 17]) # returns an array for objects with IDs in (7, 17)
Person.find([1]) # returns an array for the object with ID = 1
Person.find(1, :conditions => "administrator = 1", :order => "created_on DESC")
Note that returned records may not be in the same order as the ids you provide since database rows are unordered. Give an explicit :order
to ensure the results are sorted.
Examples
# find first
Person.find(:first) # returns the first object fetched by SELECT * FROM people
Person.find(:first, :conditions => [ "user_name = ?", user_name])
Person.find(:first, :order => "created_on DESC", :offset => 5)
# find last
Person.find(:last) # returns the last object fetched by SELECT * FROM people
Person.find(:last, :conditions => [ "user_name = ?", user_name])
Person.find(:last, :order => "created_on DESC", :offset => 5)
# find all
Person.find(:all) # returns an array of objects for all the rows fetched by SELECT * FROM people
Person.find(:all, :conditions => [ "category IN (?)", categories], :limit => 50)
Person.find(:all, :conditions => { :friends => ["Bob", "Steve", "Fred"] }
Person.find(:all, :offset => 10, :limit => 10)
Person.find(:all, :include => [ :account, :friends ])
Person.find(:all, :group => "category")
Example for find with a lock: Imagine two concurrent transactions: each will read person.visits == 2
, add 1 to it, and save, resulting in two saves of person.visits = 3
. By locking the row, the second transaction has to wait until the first is finished; we get the expected person.visits == 4
.
Person.transaction do
person = Person.find(1, :lock => true)
person.visits += 1
person.save!
end
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# File 'lib/active_record/base.rb', line 532 def find(*args) = args. () set_readonly_option!() case args.first when :first then find_initial() when :last then find_last() when :all then find_every() else find_from_ids(args, ) end end |
.find_by_sql(sql) ⇒ Object
Executes a custom SQL query against your database and returns all the results. The results will be returned as an array with columns requested encapsulated as attributes of the model you call this method from. If you call Product.find_by_sql
then the results will be returned in a Product object with the attributes you specified in the SQL query.
If you call a complicated SQL query which spans multiple tables the columns specified by the SELECT will be attributes of the model, whether or not they are columns of the corresponding table.
The sql
parameter is a full SQL query as a string. It will be called as is, there will be no database agnostic conversions performed. This should be a last resort because using, for example, MySQL specific terms will lock you to using that particular database engine or require you to change your call if you switch engines
Examples
# A simple SQL query spanning multiple tables
Post.find_by_sql "SELECT p.title, c.author FROM posts p, comments c WHERE p.id = c.post_id"
> [#<Post:0x36bff9c @attributes={"title"=>"Ruby Meetup", "first_name"=>"Quentin"}>, ...]
# You can use the same string replacement techniques as you can with ActiveRecord#find
Post.find_by_sql ["SELECT title FROM posts WHERE author = ? AND created > ?", author_id, start_date]
> [#<Post:0x36bff9c @attributes={"first_name"=>"The Cheap Man Buys Twice"}>, ...]
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# File 'lib/active_record/base.rb', line 585 def find_by_sql(sql) connection.select_all(sanitize_sql(sql), "#{name} Load").collect! { |record| instantiate(record) } end |
.finder_needs_type_condition? ⇒ Boolean
:nodoc:
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# File 'lib/active_record/base.rb', line 1211 def finder_needs_type_condition? #:nodoc: # This is like this because benchmarking justifies the strange :false stuff :true == (@finder_needs_type_condition ||= descends_from_active_record? ? :false : :true) end |
.first(*args) ⇒ Object
A convenience wrapper for find(:first, *args)
. You can pass in all the same arguments to this method as you can to find(:first)
.
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# File 'lib/active_record/base.rb', line 547 def first(*args) find(:first, *args) end |
.get_primary_key(base_name) ⇒ Object
:nodoc:
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# File 'lib/active_record/base.rb', line 1048 def get_primary_key(base_name) #:nodoc: key = 'id' case primary_key_prefix_type when :table_name key = base_name.to_s.foreign_key(false) when :table_name_with_underscore key = base_name.to_s.foreign_key end key end |
.human_attribute_name(attribute_key_name) ⇒ Object
Transforms attribute key names into a more humane format, such as “First name” instead of “first_name”. Example:
Person.human_attribute_name("first_name") # => "First name"
Deprecated in favor of just calling “first_name”.humanize
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# File 'lib/active_record/base.rb', line 1198 def human_attribute_name(attribute_key_name) #:nodoc: attribute_key_name.humanize end |
.increment_counter(counter_name, id) ⇒ Object
Increment a number field by one, usually representing a count.
This is used for caching aggregate values, so that they don’t need to be computed every time. For example, a DiscussionBoard may cache post_count and comment_count otherwise every time the board is shown it would have to run an SQL query to find how many posts and comments there are.
Attributes
-
counter_name
- The name of the field that should be incremented. -
id
- The id of the object that should be incremented.
Examples
# Increment the post_count column for the record with an id of 5
DiscussionBoard.increment_counter(:post_count, 5)
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# File 'lib/active_record/base.rb', line 855 def increment_counter(counter_name, id) update_counters(id, counter_name => 1) end |
.inheritance_column ⇒ Object
Defines the column name for use with single table inheritance – can be set in subclasses like so: self.inheritance_column = “type_id”
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# File 'lib/active_record/base.rb', line 1061 def inheritance_column @inheritance_column ||= "type".freeze end |
.inherited(child) ⇒ Object
:nodoc:
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# File 'lib/active_record/base.rb', line 366 def self.inherited(child) #:nodoc: @@subclasses[self] ||= [] @@subclasses[self] << child super end |
.inspect ⇒ Object
Returns a string like ‘Post id:integer, title:string, body:text’
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# File 'lib/active_record/base.rb', line 1217 def inspect if self == Base super elsif abstract_class? "#{super}(abstract)" elsif table_exists? attr_list = columns.map { |c| "#{c.name}: #{c.type}" } * ', ' "#{super}(#{attr_list})" else "#{super}(Table doesn't exist)" end end |
.last(*args) ⇒ Object
A convenience wrapper for find(:last, *args)
. You can pass in all the same arguments to this method as you can to find(:last)
.
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# File 'lib/active_record/base.rb', line 553 def last(*args) find(:last, *args) end |
.log_connections ⇒ Object
connection state logging
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# File 'lib/active_record/connection_adapters/abstract/connection_specification.rb', line 301 def self.log_connections #:nodoc: if logger logger.info "Defined connections: #{@@defined_connections.inspect}" logger.info "Active connections: #{active_connections.inspect}" logger.info "Active connection name: #{@active_connection_name}" end end |
.mysql_connection(config) ⇒ Object
Establishes a connection to the database that’s used by all Active Record objects.
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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 67 def self.mysql_connection(config) # :nodoc: config = config.symbolize_keys host = config[:host] port = config[:port] socket = config[:socket] username = config[:username] ? config[:username].to_s : 'root' password = config[:password].to_s if config.has_key?(:database) database = config[:database] else raise ArgumentError, "No database specified. Missing argument: database." end require_mysql mysql = Mysql.init mysql.ssl_set(config[:sslkey], config[:sslcert], config[:sslca], config[:sslcapath], config[:sslcipher]) if config[:sslkey] ConnectionAdapters::MysqlAdapter.new(mysql, logger, [host, username, password, database, port, socket], config) end |
.postgresql_connection(config) ⇒ Object
Establishes a connection to the database that’s used by all Active Record objects
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 22 def self.postgresql_connection(config) # :nodoc: config = config.symbolize_keys host = config[:host] port = config[:port] || 5432 username = config[:username].to_s if config[:username] password = config[:password].to_s if config[:password] if config.has_key?(:database) database = config[:database] else raise ArgumentError, "No database specified. Missing argument: database." end # The postgres drivers don't allow the creation of an unconnected PGconn object, # so just pass a nil connection object for the time being. ConnectionAdapters::PostgreSQLAdapter.new(nil, logger, [host, port, nil, nil, database, username, password], config) end |
.primary_key ⇒ Object
Defines the primary key field – can be overridden in subclasses. Overwriting will negate any effect of the primary_key_prefix_type setting, though.
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# File 'lib/active_record/base.rb', line 1038 def primary_key reset_primary_key end |
.protected_attributes ⇒ Object
Returns an array of all the attributes that have been protected from mass-assignment.
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# File 'lib/active_record/base.rb', line 906 def protected_attributes # :nodoc: read_inheritable_attribute("attr_protected") end |
.quote_value(value, column = nil) ⇒ Object
:nodoc:
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# File 'lib/active_record/base.rb', line 1231 def quote_value(value, column = nil) #:nodoc: connection.quote(value,column) end |
.readonly_attributes ⇒ Object
Returns an array of all the attributes that have been specified as readonly.
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# File 'lib/active_record/base.rb', line 949 def readonly_attributes read_inheritable_attribute("attr_readonly") end |
.remove_connection(klass = self) ⇒ Object
Remove the connection for this class. This will close the active connection and the defined connection (if they exist). The result can be used as an argument for establish_connection, for easily re-establishing the connection.
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# File 'lib/active_record/connection_adapters/abstract/connection_specification.rb', line 277 def self.remove_connection(klass=self) spec = @@defined_connections[klass.name] konn = active_connections[klass.name] @@defined_connections.delete_if { |key, value| value == spec } active_connections.delete_if { |key, value| value == konn } konn.disconnect! if konn spec.config if spec end |
.require_mysql ⇒ Object
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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 45 def self.require_mysql # Include the MySQL driver if one hasn't already been loaded unless defined? Mysql begin require_library_or_gem 'mysql' rescue LoadError => cannot_require_mysql # Use the bundled Ruby/MySQL driver if no driver is already in place begin ActiveSupport::Deprecation.warn "You're using the Ruby-based MySQL library that ships with Rails. This library will be REMOVED FROM RAILS 2.2. Please switch to the offical mysql gem: `gem install mysql`", caller require 'active_record/vendor/mysql' rescue LoadError raise cannot_require_mysql end end end # Define Mysql::Result.all_hashes MysqlCompat.define_all_hashes_method! end |
.reset_column_information ⇒ Object
Resets all the cached information about columns, which will cause them to be reloaded on the next request.
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# File 'lib/active_record/base.rb', line 1186 def reset_column_information generated_methods.each { |name| undef_method(name) } @column_names = @columns = @columns_hash = @content_columns = @dynamic_methods_hash = @generated_methods = @inheritance_column = nil end |
.reset_column_information_and_inheritable_attributes_for_all_subclasses ⇒ Object
:nodoc:
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# File 'lib/active_record/base.rb', line 1191 def reset_column_information_and_inheritable_attributes_for_all_subclasses#:nodoc: subclasses.each { |klass| klass.reset_inheritable_attributes; klass.reset_column_information } end |
.reset_primary_key ⇒ Object
:nodoc:
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# File 'lib/active_record/base.rb', line 1042 def reset_primary_key #:nodoc: key = get_primary_key(base_class.name) set_primary_key(key) key end |
.reset_sequence_name ⇒ Object
:nodoc:
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# File 'lib/active_record/base.rb', line 1071 def reset_sequence_name #:nodoc: default = connection.default_sequence_name(table_name, primary_key) set_sequence_name(default) default end |
.reset_subclasses ⇒ Object
:nodoc:
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# File 'lib/active_record/base.rb', line 372 def self.reset_subclasses #:nodoc: nonreloadables = [] subclasses.each do |klass| unless ActiveSupport::Dependencies.autoloaded? klass nonreloadables << klass next end klass.instance_variables.each { |var| klass.send(:remove_instance_variable, var) } klass.instance_methods(false).each { |m| klass.send :undef_method, m } end @@subclasses = {} nonreloadables.each { |klass| (@@subclasses[klass.superclass] ||= []) << klass } end |
.reset_table_name ⇒ Object
:nodoc:
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# File 'lib/active_record/base.rb', line 1015 def reset_table_name #:nodoc: base = base_class name = # STI subclasses always use their superclass' table. unless self == base base.table_name else # Nested classes are prefixed with singular parent table name. if parent < ActiveRecord::Base && !parent.abstract_class? contained = parent.table_name contained = contained.singularize if parent.pluralize_table_names contained << '_' end name = "#{table_name_prefix}#{contained}#{undecorated_table_name(base.name)}#{table_name_suffix}" end set_table_name(name) name end |
.respond_to?(method_id, include_private = false) ⇒ Boolean
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# File 'lib/active_record/base.rb', line 1293 def respond_to?(method_id, include_private = false) if match = matches_dynamic_finder?(method_id) || matches_dynamic_finder_with_initialize_or_create?(method_id) return true if all_attributes_exists?(extract_attribute_names_from_match(match)) end super end |
.retrieve_connection ⇒ Object
Locate the connection of the nearest super class. This can be an active or defined connection: if it is the latter, it will be opened and set as the active connection for the class it was defined for (not necessarily the current class).
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# File 'lib/active_record/connection_adapters/abstract/connection_specification.rb', line 250 def self.retrieve_connection #:nodoc: # Name is nil if establish_connection hasn't been called for # some class along the inheritance chain up to AR::Base yet. if name = active_connection_name if conn = active_connections[name] # Verify the connection. conn.verify!(@@verification_timeout) elsif spec = @@defined_connections[name] # Activate this connection specification. klass = name.constantize klass.connection = spec conn = active_connections[name] end end conn or raise ConnectionNotEstablished end |
.sanitize(object) ⇒ Object
Used to sanitize objects before they’re used in an SQL SELECT statement. Delegates to connection.quote
.
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# File 'lib/active_record/base.rb', line 1236 def sanitize(object) #:nodoc: connection.quote(object) end |
.sequence_name ⇒ Object
Lazy-set the sequence name to the connection’s default. This method is only ever called once since set_sequence_name overrides it.
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# File 'lib/active_record/base.rb', line 1067 def sequence_name #:nodoc: reset_sequence_name end |
.serialize(attr_name, class_name = Object) ⇒ Object
If you have an attribute that needs to be saved to the database as an object, and retrieved as the same object, then specify the name of that attribute using this method and it will be handled automatically. The serialization is done through YAML. If class_name
is specified, the serialized object must be of that class on retrieval or SerializationTypeMismatch will be raised.
Attributes
-
attr_name
- The field name that should be serialized. -
class_name
- Optional, class name that the object type should be equal to.
Example
# Serialize a preferences attribute
class User
serialize :preferences
end
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# File 'lib/active_record/base.rb', line 968 def serialize(attr_name, class_name = Object) serialized_attributes[attr_name.to_s] = class_name end |
.serialized_attributes ⇒ Object
Returns a hash of all the attributes that have been specified for serialization as keys and their class restriction as values.
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# File 'lib/active_record/base.rb', line 973 def serialized_attributes read_inheritable_attribute("attr_serialized") or write_inheritable_attribute("attr_serialized", {}) end |
.set_inheritance_column(value = nil, &block) ⇒ Object Also known as: inheritance_column=
Sets the name of the inheritance column to use to the given value, or (if the value # is nil or false) to the value returned by the given block.
class Project < ActiveRecord::Base
set_inheritance_column do
original_inheritance_column + "_id"
end
end
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# File 'lib/active_record/base.rb', line 1109 def set_inheritance_column(value = nil, &block) define_attr_method :inheritance_column, value, &block end |
.set_primary_key(value = nil, &block) ⇒ Object Also known as: primary_key=
Sets the name of the primary key column to use to the given value, or (if the value is nil or false) to the value returned by the given block.
class Project < ActiveRecord::Base
set_primary_key "sysid"
end
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# File 'lib/active_record/base.rb', line 1095 def set_primary_key(value = nil, &block) define_attr_method :primary_key, value, &block end |
.set_sequence_name(value = nil, &block) ⇒ Object Also known as: sequence_name=
Sets the name of the sequence to use when generating ids to the given value, or (if the value is nil or false) to the value returned by the given block. This is required for Oracle and is useful for any database which relies on sequences for primary key generation.
If a sequence name is not explicitly set when using Oracle or Firebird, it will default to the commonly used pattern of: #table_name_seq
If a sequence name is not explicitly set when using PostgreSQL, it will discover the sequence corresponding to your primary key for you.
class Project < ActiveRecord::Base
set_sequence_name "projectseq" # default would have been "project_seq"
end
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# File 'lib/active_record/base.rb', line 1128 def set_sequence_name(value = nil, &block) define_attr_method :sequence_name, value, &block end |
.set_table_name(value = nil, &block) ⇒ Object Also known as: table_name=
Sets the table name to use to the given value, or (if the value is nil or false) to the value returned by the given block.
class Project < ActiveRecord::Base
set_table_name "project"
end
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# File 'lib/active_record/base.rb', line 1083 def set_table_name(value = nil, &block) define_attr_method :table_name, value, &block end |
.silence ⇒ Object
Silences the logger for the duration of the block.
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# File 'lib/active_record/base.rb', line 1265 def silence old_logger_level, logger.level = logger.level, Logger::ERROR if logger yield ensure logger.level = old_logger_level if logger end |
.single_threaded_active_connections ⇒ Object
:nodoc:
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# File 'lib/active_record/connection_adapters/abstract/connection_specification.rb', line 29 def single_threaded_active_connections #:nodoc: @@active_connections end |
.sqlite3_connection(config) ⇒ Object
sqlite3 adapter reuses sqlite_connection.
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# File 'lib/active_record/connection_adapters/sqlite3_adapter.rb', line 6 def self.sqlite3_connection(config) # :nodoc: parse_sqlite_config!(config) unless self.class.const_defined?(:SQLite3) require_library_or_gem(config[:adapter]) end db = SQLite3::Database.new( config[:database], :results_as_hash => true, :type_translation => false ) db.busy_timeout(config[:timeout]) unless config[:timeout].nil? ConnectionAdapters::SQLite3Adapter.new(db, logger) end |
.sqlite_connection(config) ⇒ Object
Establishes a connection to the database that’s used by all Active Record objects
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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 7 def sqlite_connection(config) # :nodoc: parse_sqlite_config!(config) unless self.class.const_defined?(:SQLite) require_library_or_gem(config[:adapter]) db = SQLite::Database.new(config[:database], 0) db.show_datatypes = "ON" if !defined? SQLite::Version db.results_as_hash = true if defined? SQLite::Version db.type_translation = false # "Downgrade" deprecated sqlite API if SQLite.const_defined?(:Version) ConnectionAdapters::SQLite2Adapter.new(db, logger) else ConnectionAdapters::DeprecatedSQLiteAdapter.new(db, logger) end end end |
.sti_name ⇒ Object
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# File 'lib/active_record/base.rb', line 1300 def sti_name store_full_sti_class ? name : name.demodulize end |
.table_exists? ⇒ Boolean
Indicates whether the table associated with this class exists
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# File 'lib/active_record/base.rb', line 1142 def table_exists? connection.table_exists?(table_name) end |
.table_name ⇒ Object
Guesses the table name (in forced lower-case) based on the name of the class in the inheritance hierarchy descending directly from ActiveRecord::Base. So if the hierarchy looks like: Reply < Message < ActiveRecord::Base, then Message is used to guess the table name even when called on Reply. The rules used to do the guess are handled by the Inflector class in Active Support, which knows almost all common English inflections. You can add new inflections in config/initializers/inflections.rb.
Nested classes are given table names prefixed by the singular form of the parent’s table name. Enclosing modules are not considered.
Examples
class Invoice < ActiveRecord::Base; end;
file class table_name
invoice.rb Invoice invoices
class Invoice < ActiveRecord::Base; class Lineitem < ActiveRecord::Base; end; end;
file class table_name
invoice.rb Invoice::Lineitem invoice_lineitems
module Invoice; class Lineitem < ActiveRecord::Base; end; end;
file class table_name
invoice/lineitem.rb Invoice::Lineitem lineitems
Additionally, the class-level table_name_prefix
is prepended and the table_name_suffix
is appended. So if you have “myapp_” as a prefix, the table name guess for an Invoice class becomes “myapp_invoices”. Invoice::Lineitem becomes “myapp_invoice_lineitems”.
You can also overwrite this class method to allow for unguessable links, such as a Mouse class with a link to a “mice” table. Example:
class Mouse < ActiveRecord::Base
set_table_name "mice"
end
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# File 'lib/active_record/base.rb', line 1011 def table_name reset_table_name end |
.thread_safe_active_connections ⇒ Object
Retrieve the connection cache.
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# File 'lib/active_record/connection_adapters/abstract/connection_specification.rb', line 25 def thread_safe_active_connections #:nodoc: @@active_connections[Thread.current.object_id] ||= {} end |
.update(id, attributes) ⇒ Object
Updates an object (or multiple objects) and saves it to the database, if validations pass. The resulting object is returned whether the object was saved successfully to the database or not.
Attributes
-
id
- This should be the id or an array of ids to be updated. -
attributes
- This should be a Hash of attributes to be set on the object, or an array of Hashes.
Examples
# Updating one record:
Person.update(15, { :user_name => 'Samuel', :group => 'expert' })
# Updating multiple records:
people = { 1 => { "first_name" => "David" }, 2 => { "first_name" => "Jeremy" } }
Person.update(people.keys, people.values)
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# File 'lib/active_record/base.rb', line 665 def update(id, attributes) if id.is_a?(Array) idx = -1 id.collect { |one_id| idx += 1; update(one_id, attributes[idx]) } else object = find(id) object.update_attributes(attributes) object end end |
.update_all(updates, conditions = nil, options = {}) ⇒ Object
Updates all records with details given if they match a set of conditions supplied, limits and order can also be supplied.
Attributes
-
updates
- A String of column and value pairs that will be set on any records that match conditions. -
conditions
- An SQL fragment like “administrator = 1” or [ “user_name = ?”, username ]. See conditions in the intro for more info. -
options
- Additional options are:limit
and/or:order
, see the examples for usage.
Examples
# Update all billing objects with the 3 different attributes given
Billing.update_all( "category = 'authorized', approved = 1, author = 'David'" )
# Update records that match our conditions
Billing.update_all( "author = 'David'", "title LIKE '%Rails%'" )
# Update records that match our conditions but limit it to 5 ordered by date
Billing.update_all( "author = 'David'", "title LIKE '%Rails%'",
:order => 'created_at', :limit => 5 )
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# File 'lib/active_record/base.rb', line 746 def update_all(updates, conditions = nil, = {}) sql = "UPDATE #{quoted_table_name} SET #{sanitize_sql_for_assignment(updates)} " scope = scope(:find) add_conditions!(sql, conditions, scope) add_order!(sql, [:order], nil) add_limit!(sql, , nil) connection.update(sql, "#{name} Update") end |
.update_counters(id, counters) ⇒ Object
A generic “counter updater” implementation, intended primarily to be used by increment_counter and decrement_counter, but which may also be useful on its own. It simply does a direct SQL update for the record with the given ID, altering the given hash of counters by the amount given by the corresponding value:
Attributes
-
id
- The id of the object you wish to update a counter on. -
counters
- An Array of Hashes containing the names of the fields to update as keys and the amount to update the field by as values.
Examples
# For the Post with id of 5, decrement the comment_count by 1, and
# increment the action_count by 1
Post.update_counters 5, :comment_count => -1, :action_count => 1
# Executes the following SQL:
# UPDATE posts
# SET comment_count = comment_count - 1,
# action_count = action_count + 1
# WHERE id = 5
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# File 'lib/active_record/base.rb', line 832 def update_counters(id, counters) updates = counters.inject([]) { |list, (counter_name, increment)| sign = increment < 0 ? "-" : "+" list << "#{connection.quote_column_name(counter_name)} = COALESCE(#{connection.quote_column_name(counter_name)}, 0) #{sign} #{increment.abs}" }.join(", ") update_all(updates, "#{connection.quote_column_name(primary_key)} = #{quote_value(id)}") end |
.verify_active_connections! ⇒ Object
Verify active connections.
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# File 'lib/active_record/connection_adapters/abstract/connection_specification.rb', line 114 def verify_active_connections! #:nodoc: if @@allow_concurrency remove_stale_cached_threads!(@@active_connections) do |name, conn| conn.disconnect! end end active_connections.each_value do |connection| connection.verify!(@@verification_timeout) end end |
Instance Method Details
#==(comparison_object) ⇒ Object
Returns true if the comparison_object
is the same object, or is of the same type and has the same id.
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# File 'lib/active_record/base.rb', line 2431 def ==(comparison_object) comparison_object.equal?(self) || (comparison_object.instance_of?(self.class) && comparison_object.id == id && !comparison_object.new_record?) end |
#[](attr_name) ⇒ Object
Returns the value of the attribute identified by attr_name
after it has been typecast (for example, “2004-12-12” in a data column is cast to a date object, like Date.new(2004, 12, 12)). (Alias for the protected read_attribute method).
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# File 'lib/active_record/base.rb', line 2348 def [](attr_name) read_attribute(attr_name) end |
#[]=(attr_name, value) ⇒ Object
Updates the attribute identified by attr_name
with the specified value
. (Alias for the protected write_attribute method).
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# File 'lib/active_record/base.rb', line 2354 def []=(attr_name, value) write_attribute(attr_name, value) end |
#attribute_for_inspect(attr_name) ⇒ Object
Format attributes nicely for inspect.
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# File 'lib/active_record/base.rb', line 2396 def attribute_for_inspect(attr_name) value = read_attribute(attr_name) if value.is_a?(String) && value.length > 50 "#{value[0..50]}...".inspect elsif value.is_a?(Date) || value.is_a?(Time) %("#{value.to_s(:db)}") else value.inspect end end |
#attribute_names ⇒ Object
Returns an array of names for the attributes available on this object sorted alphabetically.
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# File 'lib/active_record/base.rb', line 2421 def attribute_names @attributes.keys.sort end |
#attribute_present?(attribute) ⇒ Boolean
Returns true if the specified attribute
has been set by the user or by a database load and is neither nil nor empty? (the latter only applies to objects that respond to empty?, most notably Strings).
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# File 'lib/active_record/base.rb', line 2410 def attribute_present?(attribute) value = read_attribute(attribute) !value.blank? end |
#attributes ⇒ Object
Returns a hash of all the attributes with their names as keys and the values of the attributes as values.
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# File 'lib/active_record/base.rb', line 2380 def attributes self.attribute_names.inject({}) do |attrs, name| attrs[name] = read_attribute(name) attrs end end |
#attributes=(new_attributes, guard_protected_attributes = true) ⇒ Object
Allows you to set all the attributes at once by passing in a hash with keys matching the attribute names (which again matches the column names). Sensitive attributes can be protected from this form of mass-assignment by using the attr_protected
macro. Or you can alternatively specify which attributes can be accessed with the attr_accessible
macro. Then all the attributes not included in that won’t be allowed to be mass-assigned.
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# File 'lib/active_record/base.rb', line 2363 def attributes=(new_attributes, guard_protected_attributes = true) return if new_attributes.nil? attributes = new_attributes.dup attributes.stringify_keys! multi_parameter_attributes = [] attributes = remove_attributes_protected_from_mass_assignment(attributes) if guard_protected_attributes attributes.each do |k, v| k.include?("(") ? multi_parameter_attributes << [ k, v ] : send(k + "=", v) end assign_multiparameter_attributes(multi_parameter_attributes) end |
#attributes_before_type_cast ⇒ Object
Returns a hash of attributes before typecasting and deserialization.
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# File 'lib/active_record/base.rb', line 2388 def attributes_before_type_cast self.attribute_names.inject({}) do |attrs, name| attrs[name] = read_attribute_before_type_cast(name) attrs end end |
#becomes(klass) ⇒ Object
Returns an instance of the specified klass
with the attributes of the current record. This is mostly useful in relation to single-table inheritance structures where you want a subclass to appear as the superclass. This can be used along with record identification in Action Pack to allow, say, Client < Company
to do something like render :partial => @client.becomes(Company)
to render that instance using the companies/company partial instead of clients/client.
Note: The new instance will share a link to the same attributes as the original class. So any change to the attributes in either instance will affect the other.
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# File 'lib/active_record/base.rb', line 2253 def becomes(klass) returning klass.new do |became| became.instance_variable_set("@attributes", @attributes) became.instance_variable_set("@attributes_cache", @attributes_cache) became.instance_variable_set("@new_record", new_record?) end end |
#cache_key ⇒ Object
Returns a cache key that can be used to identify this record.
Examples
Product.new.cache_key # => "products/new"
Product.find(5).cache_key # => "products/5" (updated_at not available)
Person.find(5).cache_key # => "people/5-20071224150000" (updated_at available)
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# File 'lib/active_record/base.rb', line 2173 def cache_key case when new_record? "#{self.class.name.tableize}/new" when self[:updated_at] "#{self.class.name.tableize}/#{id}-#{updated_at.to_s(:number)}" else "#{self.class.name.tableize}/#{id}" end end |
#clone ⇒ Object
Returns a clone of the record that hasn’t been assigned an id yet and is treated as a new record. Note that this is a “shallow” clone: it copies the object’s attributes only, not its associations. The extent of a “deep” clone is application-specific and is therefore left to the application to implement according to its need.
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# File 'lib/active_record/base.rb', line 2238 def clone attrs = clone_attributes(:read_attribute_before_type_cast) attrs.delete(self.class.primary_key) record = self.class.new record.send :instance_variable_set, '@attributes', attrs record end |
#column_for_attribute(name) ⇒ Object
Returns the column object for the named attribute.
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# File 'lib/active_record/base.rb', line 2426 def column_for_attribute(name) self.class.columns_hash[name.to_s] end |
#connection ⇒ Object
Returns the connection currently associated with the class. This can also be used to “borrow” the connection to do database work that isn’t easily done without going straight to SQL.
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# File 'lib/active_record/connection_adapters/abstract/connection_specification.rb', line 173 def connection self.class.connection end |
#decrement(attribute, by = 1) ⇒ Object
Initializes attribute
to zero if nil
and subtracts the value passed as by
(default is 1). The decrement is performed directly on the underlying attribute, no setter is invoked. Only makes sense for number-based attributes. Returns self
.
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# File 'lib/active_record/base.rb', line 2302 def decrement(attribute, by = 1) self[attribute] ||= 0 self[attribute] -= by self end |
#decrement!(attribute, by = 1) ⇒ Object
Wrapper around decrement
that saves the record. This method differs from its non-bang version in that it passes through the attribute setter. Saving is not subjected to validation checks. Returns true
if the record could be saved.
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# File 'lib/active_record/base.rb', line 2312 def decrement!(attribute, by = 1) decrement(attribute, by).update_attribute(attribute, self[attribute]) end |
#destroy ⇒ Object
Deletes the record in the database and freezes this instance to reflect that no changes should be made (since they can’t be persisted).
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# File 'lib/active_record/base.rb', line 2222 def destroy unless new_record? connection.delete <<-end_sql, "#{self.class.name} Destroy" DELETE FROM #{self.class.quoted_table_name} WHERE #{connection.quote_column_name(self.class.primary_key)} = #{quoted_id} end_sql end freeze end |
#eql?(comparison_object) ⇒ Boolean
Delegates to ==
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# File 'lib/active_record/base.rb', line 2439 def eql?(comparison_object) self == (comparison_object) end |
#freeze ⇒ Object
Freeze the attributes hash such that associations are still accessible, even on destroyed records.
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# File 'lib/active_record/base.rb', line 2450 def freeze @attributes.freeze; self end |
#frozen? ⇒ Boolean
Returns true
if the attributes hash has been frozen.
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# File 'lib/active_record/base.rb', line 2455 def frozen? @attributes.frozen? end |
#has_attribute?(attr_name) ⇒ Boolean
Returns true if the given attribute is in the attributes hash
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# File 'lib/active_record/base.rb', line 2416 def has_attribute?(attr_name) @attributes.has_key?(attr_name.to_s) end |
#hash ⇒ Object
Delegates to id in order to allow two records of the same type and id to work with something like:
[ Person.find(1), Person.find(2), Person.find(3) ] & [ Person.find(1), Person.find(4) ] # => [ Person.find(1) ]
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# File 'lib/active_record/base.rb', line 2445 def hash id.hash end |
#id ⇒ Object
A model instance’s primary key is always available as model.id whether you name it the default ‘id’ or set it to something else.
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# File 'lib/active_record/base.rb', line 2150 def id attr_name = self.class.primary_key column = column_for_attribute(attr_name) self.class.send(:define_read_method, :id, attr_name, column) # now that the method exists, call it self.send attr_name.to_sym end |
#id=(value) ⇒ Object
Sets the primary ID.
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# File 'lib/active_record/base.rb', line 2193 def id=(value) write_attribute(self.class.primary_key, value) end |
#id_before_type_cast ⇒ Object
:nodoc:
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# File 'lib/active_record/base.rb', line 2184 def id_before_type_cast #:nodoc: read_attribute_before_type_cast(self.class.primary_key) end |
#increment(attribute, by = 1) ⇒ Object
Initializes attribute
to zero if nil
and adds the value passed as by
(default is 1). The increment is performed directly on the underlying attribute, no setter is invoked. Only makes sense for number-based attributes. Returns self
.
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# File 'lib/active_record/base.rb', line 2285 def increment(attribute, by = 1) self[attribute] ||= 0 self[attribute] += by self end |
#increment!(attribute, by = 1) ⇒ Object
Wrapper around increment
that saves the record. This method differs from its non-bang version in that it passes through the attribute setter. Saving is not subjected to validation checks. Returns true
if the record could be saved.
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# File 'lib/active_record/base.rb', line 2295 def increment!(attribute, by = 1) increment(attribute, by).update_attribute(attribute, self[attribute]) end |
#inspect ⇒ Object
Returns the contents of the record as a nicely formatted string.
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# File 'lib/active_record/base.rb', line 2471 def inspect attributes_as_nice_string = self.class.column_names.collect { |name| if has_attribute?(name) || new_record? "#{name}: #{attribute_for_inspect(name)}" end }.compact.join(", ") "#<#{self.class} #{attributes_as_nice_string}>" end |
#new_record? ⇒ Boolean
Returns true if this object hasn’t been saved yet – that is, a record for the object doesn’t exist yet.
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# File 'lib/active_record/base.rb', line 2198 def new_record? defined?(@new_record) && @new_record end |
#quoted_id ⇒ Object
:nodoc:
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# File 'lib/active_record/base.rb', line 2188 def quoted_id #:nodoc: quote_value(id, column_for_attribute(self.class.primary_key)) end |
#readonly! ⇒ Object
Marks this record as read only.
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# File 'lib/active_record/base.rb', line 2466 def readonly! @readonly = true end |
#readonly? ⇒ Boolean
Returns true
if the record is read only. Records loaded through joins with piggy-back attributes will be marked as read only since they cannot be saved.
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# File 'lib/active_record/base.rb', line 2461 def readonly? defined?(@readonly) && @readonly == true end |
#reload(options = nil) ⇒ Object
Reloads the attributes of this object from the database. The optional options argument is passed to find when reloading so you may do e.g. record.reload(:lock => true) to reload the same record with an exclusive row lock.
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# File 'lib/active_record/base.rb', line 2337 def reload( = nil) clear_aggregation_cache clear_association_cache @attributes.update(self.class.find(self.id, ).instance_variable_get('@attributes')) @attributes_cache = {} self end |
#save ⇒ Object
-
No record exists: Creates a new record with values matching those of the object attributes.
-
A record does exist: Updates the record with values matching those of the object attributes.
Note: If your model specifies any validations then the method declaration dynamically changes to:
save(perform_validation=true)
Calling save(false) saves the model without running validations. See ActiveRecord::Validations for more information.
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# File 'lib/active_record/base.rb', line 2210 def save create_or_update end |
#save! ⇒ Object
Attempts to save the record, but instead of just returning false if it couldn’t happen, it raises a RecordNotSaved exception
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# File 'lib/active_record/base.rb', line 2216 def save! create_or_update || raise(RecordNotSaved) end |
#to_param ⇒ Object
Enables Active Record objects to be used as URL parameters in Action Pack automatically.
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# File 'lib/active_record/base.rb', line 2161 def to_param # We can't use alias_method here, because method 'id' optimizes itself on the fly. (id = self.id) ? id.to_s : nil # Be sure to stringify the id for routes end |
#toggle(attribute) ⇒ Object
Assigns to attribute
the boolean opposite of attribute?
. So if the predicate returns true
the attribute will become false
. This method toggles directly the underlying value without calling any setter. Returns self
.
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# File 'lib/active_record/base.rb', line 2320 def toggle(attribute) self[attribute] = !send("#{attribute}?") self end |
#toggle!(attribute) ⇒ Object
Wrapper around toggle
that saves the record. This method differs from its non-bang version in that it passes through the attribute setter. Saving is not subjected to validation checks. Returns true
if the record could be saved.
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# File 'lib/active_record/base.rb', line 2329 def toggle!(attribute) toggle(attribute).update_attribute(attribute, self[attribute]) end |
#update_attribute(name, value) ⇒ Object
Updates a single attribute and saves the record. This is especially useful for boolean flags on existing records. Note: This method is overwritten by the Validation module that’ll make sure that updates made with this method aren’t subjected to validation checks. Hence, attributes can be updated even if the full object isn’t valid.
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# File 'lib/active_record/base.rb', line 2264 def update_attribute(name, value) send(name.to_s + '=', value) save end |
#update_attributes(attributes) ⇒ Object
Updates all the attributes from the passed-in Hash and saves the record. If the object is invalid, the saving will fail and false will be returned.
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# File 'lib/active_record/base.rb', line 2271 def update_attributes(attributes) self.attributes = attributes save end |
#update_attributes!(attributes) ⇒ Object
Updates an object just like Base.update_attributes but calls save! instead of save so an exception is raised if the record is invalid.
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# File 'lib/active_record/base.rb', line 2277 def update_attributes!(attributes) self.attributes = attributes save! end |