Class: ActiveRecord::Base
- Defined in:
- activerecord/lib/active_record/base.rb,
activerecord/lib/active_record/connection_adapters/mysql_adapter.rb,
activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb,
activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb,
activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb,
activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb
Overview
Active Record
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/activerecord/README_rdoc.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)
where("user_name = '#{user_name}' AND password = '#{password}'").first
end
def self.authenticate_safely(user_name, password)
where("user_name = ? AND password = ?", user_name, password).first
end
def self.authenticate_safely_simply(user_name, password)
where(:user_name => user_name, :password => password).first
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.where(
"id = :id AND name = :name AND division = :division AND created_at > :accounting_date",
{ :id => 3, :name => "37signals", :division => "First", :accounting_date => '2005-01-01' }
).first
Similarly, a simple hash without a statement will generate conditions based on equality with the SQL AND operator. For instance:
Student.where(:first_name => "Harvey", :status => 1)
Student.where(params[:student])
A range may be used in the hash to use the SQL BETWEEN operator:
Student.where(:grade => 9..12)
An array may be used in the hash to use the SQL IN operator:
Student.where(:grade => [9,11,12])
When joining tables, nested hashes or keys written in the form ‘table_name.column_name’ can be used to qualify the table name of a particular condition. For instance:
Student.joins(:schools).where(:schools => { :type => 'public' })
Student.joins(:schools).where('schools.type' => 'public' )
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.
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)
.
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_
, find_last_by_
, or find_all_by_
and thus produces finders like Person.find_by_user_name
, Person.find_all_by_last_name
, and Payment.find_by_transaction_id
. Instead of writing Person.where(:user_name => user_name).first
, you just do Person.find_by_user_name(user_name)
. And instead of writing Person.where(:last_name => last_name).all
, 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”.
Person.where(:user_name => user_name, :password => password).first
Person.find_by_user_name_and_password(user_name, password) # with dynamic finder
It’s even possible to call these dynamic finder methods on relations and named scopes.
Payment.order("created_on").find_all_by_amount(50)
Payment.pending.find_last_by_amount(100)
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.
# 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 set unless they are given in a block.
# No 'Winter' tag exists
winter = Tag.find_or_initialize_by_name("Winter")
winter.persisted? # false
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.
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.
Just like find_by_*
, you can also use scoped_by_*
to retrieve data. The good thing about using this feature is that the very first time result is returned using method_missing
technique but after that the method is declared on the class. Henceforth method_missing
will not be hit.
User.scoped_by_user_name('David')
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.
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 descendant of a class not in the hierarchy.
class User < ActiveRecord::Base
serialize :preferences, Hash
end
user = User.create(:preferences => %w( one two three ))
User.find(user.id).preferences # raises SerializationTypeMismatch
When you specify a class option, the default value for that attribute will be a new instance of that class.
class User < ActiveRecord::Base
serialize :preferences, OpenStruct
end
user = User.new
user.preferences.theme_color = "red"
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.where(:name => '37signals').first
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.
Direct Known Subclasses
Defined Under Namespace
Classes: ConnectionSpecification
Constant Summary collapse
- @@configurations =
{}
- @@primary_key_prefix_type =
nil
- @@default_timezone =
:local
- @@schema_format =
:ruby
- @@timestamped_migrations =
true
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 an abstract class or not.
- .arel_engine ⇒ Object
- .arel_table ⇒ Object
-
.attr_readonly(*attributes) ⇒ Object
Attributes listed as readonly will be used to create a new record but update operations will ignore these fields.
- .attribute_method?(attribute) ⇒ Boolean
-
.attribute_names ⇒ Object
Returns an array of column names as strings if it’s not an abstract class and table exists.
-
.base_class ⇒ Object
Returns the base AR subclass that this class descends from.
-
.before_remove_const ⇒ Object
:nodoc:.
- .clear_active_connections! ⇒ Object
-
.clear_cache! ⇒ Object
:nodoc:.
-
.column_defaults ⇒ Object
Returns a hash where the keys are column names and the values are default values when instantiating the AR object for this table.
-
.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 Active Record is connected.
-
.connection ⇒ Object
Returns the connection currently associated with the class.
-
.connection_config ⇒ Object
Returns the configuration of the associated connection as a hash:.
- .connection_pool ⇒ Object
-
.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, options = {}, &block) ⇒ Object
Creates an object (or multiple objects) and saves it to the database, if validations pass.
-
.descends_from_active_record? ⇒ Boolean
True if this isn’t a concrete subclass needing a STI type condition.
-
.establish_connection(spec = nil) ⇒ Object
Establishes the connection to the database.
-
.find_by_sql(sql, binds = []) ⇒ Object
Executes a custom SQL query against your database and returns all the results.
-
.finder_needs_type_condition? ⇒ Boolean
:nodoc:.
-
.full_table_name_prefix ⇒ Object
:nodoc:.
-
.i18n_scope ⇒ Object
Set the i18n scope to overwrite ActiveModel.
-
.inheritance_column ⇒ Object
Defines the column name for use with single table inheritance.
-
.inspect ⇒ Object
Returns a string like ‘Post(id:integer, title:string, body:text)’.
-
.instantiate(record) ⇒ Object
Finder methods must instantiate through this method to work with the single-table inheritance model that makes it possible to create objects of different types from the same table.
-
.lookup_ancestors ⇒ Object
Set the lookup ancestors for ActiveModel.
-
.mysql2_connection(config) ⇒ Object
Establishes a connection to the database that’s used by all Active Record objects.
-
.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.
-
.quote_value(value, column = nil) ⇒ Object
:nodoc:.
-
.quoted_table_name ⇒ Object
Returns a quoted version of the table name, used to construct SQL statements.
-
.readonly_attributes ⇒ Object
Returns an array of all the attributes that have been specified as readonly.
- .remove_connection(klass = self) ⇒ Object
-
.reset_column_information ⇒ Object
Resets all the cached information about columns, which will cause them to be reloaded on the next request.
-
.reset_sequence_name ⇒ Object
:nodoc:.
-
.reset_table_name ⇒ Object
Computes the table name, (re)sets it internally, and returns it.
- .respond_to?(method_id, include_private = false) ⇒ Boolean
- .retrieve_connection ⇒ Object
-
.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.
-
.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_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.
-
.sqlite3_connection(config) ⇒ Object
sqlite3 adapter reuses sqlite_connection.
- .sti_name ⇒ Object
- .symbolized_base_class ⇒ Object
- .symbolized_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.
-
.unscoped ⇒ Object
Returns a scope for this class without taking into account the default_scope.
Instance Method Summary collapse
-
#<=>(other_object) ⇒ Object
Allows sort on objects.
-
#==(comparison_object) ⇒ Object
(also: #eql?)
Returns true if
comparison_object
is the same exact object, orcomparison_object
is of the same type andself
has an ID and it is equal tocomparison_object.id
. -
#assign_attributes(new_attributes, options = {}) ⇒ Object
Allows you to set all the attributes for a particular mass-assignment security role by passing in a hash of attributes with keys matching the attribute names (which again matches the column names) and the role name using the :as option.
-
#attribute_for_inspect(attr_name) ⇒ Object
Returns an
#inspect
-like string for the value of the attributeattr_name
. -
#attribute_names ⇒ Object
Returns an array of names for the attributes available on this object.
-
#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 = nil) ⇒ 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).
-
#cache_key ⇒ Object
Returns a cache key that can be used to identify this record.
-
#column_for_attribute(name) ⇒ Object
Returns the column object for the named attribute.
-
#configurations ⇒ Object
:singleton-method: Contains the database configuration - as is typically stored in config/database.yml - as a Hash.
-
#connection ⇒ Object
Returns the connection currently associated with the class.
-
#connection_handler ⇒ Object
:singleton-method: The connection handler.
-
#default_timezone ⇒ Object
:singleton-method: Determines whether to use Time.local (using :local) or Time.utc (using :utc) when pulling dates and times from the database.
-
#dup ⇒ Object
:nodoc:.
-
#encode_with(coder) ⇒ Object
Populate
coder
with attributes about this record that should be serialized. -
#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) ].
-
#init_with(coder) ⇒ Object
Initialize an empty model object from
coder
. -
#initialize(attributes = nil, options = {}) {|_self| ... } ⇒ 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).
-
#initialize_dup(other) ⇒ Object
Duped objects have no id assigned and are treated as new records.
-
#inspect ⇒ Object
Returns the contents of the record as a nicely formatted string.
-
#logger ⇒ Object
:singleton-method: Accepts a logger conforming to the interface of Log4r or the default Ruby 1.8+ Logger class, which is then passed on to any new database connections made and which can be retrieved on both a class and instance level by calling
logger
. -
#pluralize_table_names ⇒ Object
:singleton-method: Indicates whether table names should be the pluralized versions of the corresponding class names.
-
#primary_key_prefix_type ⇒ Object
:singleton-method: Accessor for the prefix type that will be prepended to every primary key column name.
-
#quoted_id ⇒ Object
:nodoc:.
-
#readonly! ⇒ Object
Marks this record as read only.
-
#readonly? ⇒ Boolean
Returns
true
if the record is read only. -
#schema_format ⇒ Object
:singleton-method: Specifies the format to use when dumping the database schema with Rails’ Rakefile.
-
#table_name_prefix ⇒ Object
:singleton-method: Accessor for the name of the prefix string to prepend to every table name.
-
#table_name_suffix ⇒ Object
:singleton-method: Works like
table_name_prefix
, but appends instead of prepends (set to “_basecamp” gives “projects_basecamp”, “people_basecamp”). -
#timestamped_migrations ⇒ Object
:singleton-method: Specify whether or not to use timestamps for migration versions.
-
#to_param ⇒ Object
Returns a String, which Action Pack uses for constructing an URL to this object.
Constructor Details
#initialize(attributes = nil, options = {}) {|_self| ... } ⇒ 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.
initialize
respects mass-assignment security and accepts either :as
or :without_protection
options in the options
parameter.
Examples
# Instantiates a single new object
User.new(:first_name => 'Jamie')
# Instantiates a single new object using the :admin mass-assignment security role
User.new({ :first_name => 'Jamie', :is_admin => true }, :as => :admin)
# Instantiates a single new object bypassing mass-assignment security
User.new({ :first_name => 'Jamie', :is_admin => true }, :without_protection => true)
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# File 'activerecord/lib/active_record/base.rb', line 1549 def initialize(attributes = nil, = {}) @attributes = attributes_from_column_definition @association_cache = {} @aggregation_cache = {} @attributes_cache = {} @new_record = true @readonly = false @destroyed = false @marked_for_destruction = false @previously_changed = {} @changed_attributes = {} @relation = nil ensure_proper_type set_serialized_attributes populate_with_current_scope_attributes assign_attributes(attributes, ) if attributes yield self if block_given? run_callbacks :initialize 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 'activerecord/lib/active_record/base.rb', line 883 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 'activerecord/lib/active_record/base.rb', line 860 def ===(object) object.is_a?(self) end |
.abstract_class? ⇒ Boolean
Returns whether this class is an abstract class or not.
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# File 'activerecord/lib/active_record/base.rb', line 886 def abstract_class? defined?(@abstract_class) && @abstract_class == true end |
.arel_engine ⇒ Object
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# File 'activerecord/lib/active_record/base.rb', line 908 def arel_engine @arel_engine ||= begin if self == ActiveRecord::Base ActiveRecord::Base else connection_handler.connection_pools[name] ? self : superclass.arel_engine end end end |
.arel_table ⇒ Object
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# File 'activerecord/lib/active_record/base.rb', line 904 def arel_table @arel_table ||= Arel::Table.new(table_name, arel_engine) end |
.attr_readonly(*attributes) ⇒ Object
Attributes listed as readonly will be used to create a new record but update operations will ignore these fields.
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# File 'activerecord/lib/active_record/base.rb', line 533 def attr_readonly(*attributes) self._attr_readonly = Set.new(attributes.map { |a| a.to_s }) + (self._attr_readonly || []) end |
.attribute_method?(attribute) ⇒ Boolean
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# File 'activerecord/lib/active_record/base.rb', line 790 def attribute_method?(attribute) super || (table_exists? && column_names.include?(attribute.to_s.sub(/=$/, ''))) end |
.attribute_names ⇒ Object
Returns an array of column names as strings if it’s not an abstract class and table exists. Otherwise it returns an empty array.
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# File 'activerecord/lib/active_record/base.rb', line 797 def attribute_names @attribute_names ||= if !abstract_class? && table_exists? column_names else [] end 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.
If B < A and C < B and if A is an abstract_class then both B.base_class and C.base_class would return B as the answer since A is an abstract_class.
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# File 'activerecord/lib/active_record/base.rb', line 878 def base_class class_of_active_record_descendant(self) end |
.before_remove_const ⇒ Object
:nodoc:
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# File 'activerecord/lib/active_record/base.rb', line 945 def before_remove_const #:nodoc: self.current_scope = nil end |
.clear_active_connections! ⇒ Object
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# File 'activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb', line 119 def clear_active_connections! connection_handler.clear_active_connections! end |
.clear_cache! ⇒ Object
:nodoc:
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# File 'activerecord/lib/active_record/base.rb', line 786 def clear_cache! # :nodoc: connection_pool.clear_cache! end |
.column_defaults ⇒ Object
Returns a hash where the keys are column names and the values are default values when instantiating the AR object for this table.
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# File 'activerecord/lib/active_record/base.rb', line 722 def column_defaults connection_pool.column_defaults[table_name] 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 'activerecord/lib/active_record/base.rb', line 740 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 'activerecord/lib/active_record/base.rb', line 727 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 'activerecord/lib/active_record/base.rb', line 707 def columns if defined?(@primary_key) connection_pool.primary_keys[table_name] ||= primary_key end connection_pool.columns[table_name] end |
.columns_hash ⇒ Object
Returns a hash of column objects for the table associated with this class.
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# File 'activerecord/lib/active_record/base.rb', line 716 def columns_hash connection_pool.columns_hash[table_name] end |
.connected? ⇒ Boolean
Returns true if Active Record is connected.
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# File 'activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb', line 111 def connected? connection_handler.connected?(self) 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 'activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb', line 88 def connection retrieve_connection end |
.connection_config ⇒ Object
Returns the configuration of the associated connection as a hash:
ActiveRecord::Base.connection_config
# => {:pool=>5, :timeout=>5000, :database=>"db/development.sqlite3", :adapter=>"sqlite3"}
Please use only for reading.
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# File 'activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb', line 98 def connection_config connection_pool.spec.config end |
.connection_pool ⇒ Object
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# File 'activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb', line 102 def connection_pool connection_handler.retrieve_connection_pool(self) or raise ConnectionNotEstablished 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 'activerecord/lib/active_record/base.rb', line 733 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.
Parameters
-
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 'activerecord/lib/active_record/base.rb', line 526 def count_by_sql(sql) sql = sanitize_conditions(sql) connection.select_value(sql, "#{name} Count").to_i end |
.create(attributes = nil, options = {}, &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.
create
respects mass-assignment security and accepts either :as
or :without_protection
options in the options
parameter.
Examples
# Create a single new object
User.create(:first_name => 'Jamie')
# Create a single new object using the :admin mass-assignment security role
User.create({ :first_name => 'Jamie', :is_admin => true }, :as => :admin)
# Create a single new object bypassing mass-assignment security
User.create({ :first_name => 'Jamie', :is_admin => true }, :without_protection => true)
# 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 'activerecord/lib/active_record/base.rb', line 504 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 |
.descends_from_active_record? ⇒ Boolean
True if this isn’t a concrete subclass needing a STI type condition.
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# File 'activerecord/lib/active_record/base.rb', line 823 def descends_from_active_record? if superclass.abstract_class? superclass.descends_from_active_record? else superclass == Base || !columns_hash.include?(inheritance_column) end 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 'activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb', line 51 def self.establish_connection(spec = nil) case spec when nil raise AdapterNotSpecified unless defined?(Rails.env) establish_connection(Rails.env) when ConnectionSpecification self.connection_handler.establish_connection(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 "active_record/connection_adapters/#{spec[:adapter]}_adapter" rescue LoadError => e raise "Please install the #{spec[:adapter]} adapter: `gem install activerecord-#{spec[:adapter]}-adapter` (#{e})" end adapter_method = "#{spec[:adapter]}_connection" unless 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 |
.find_by_sql(sql, binds = []) ⇒ 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={"title"=>"The Cheap Man Buys Twice"}>, ...]
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# File 'activerecord/lib/active_record/base.rb', line 469 def find_by_sql(sql, binds = []) connection.select_all(sanitize_sql(sql), "#{name} Load", binds).collect! { |record| instantiate(record) } end |
.finder_needs_type_condition? ⇒ Boolean
:nodoc:
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# File 'activerecord/lib/active_record/base.rb', line 831 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 |
.full_table_name_prefix ⇒ Object
:nodoc:
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# File 'activerecord/lib/active_record/base.rb', line 630 def full_table_name_prefix #:nodoc: (parents.detect{ |p| p.respond_to?(:table_name_prefix) } || self).table_name_prefix end |
.i18n_scope ⇒ Object
Set the i18n scope to overwrite ActiveModel.
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# File 'activerecord/lib/active_record/base.rb', line 818 def i18n_scope #:nodoc: :activerecord end |
.inheritance_column ⇒ Object
Defines the column name for use with single table inheritance. Use set_inheritance_column
to set a different value.
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# File 'activerecord/lib/active_record/base.rb', line 636 def inheritance_column @inheritance_column ||= "type" end |
.inspect ⇒ Object
Returns a string like ‘Post(id:integer, title:string, body:text)’
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# File 'activerecord/lib/active_record/base.rb', line 837 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 |
.instantiate(record) ⇒ Object
Finder methods must instantiate through this method to work with the single-table inheritance model that makes it possible to create objects of different types from the same table.
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# File 'activerecord/lib/active_record/base.rb', line 952 def instantiate(record) sti_class = find_sti_class(record[inheritance_column]) record_id = sti_class.primary_key && record[sti_class.primary_key] if ActiveRecord::IdentityMap.enabled? && record_id if (column = sti_class.columns_hash[sti_class.primary_key]) && column.number? record_id = record_id.to_i end if instance = IdentityMap.get(sti_class, record_id) instance.reinit_with('attributes' => record) else instance = sti_class.allocate.init_with('attributes' => record) IdentityMap.add(instance) end else instance = sti_class.allocate.init_with('attributes' => record) end instance end |
.lookup_ancestors ⇒ Object
Set the lookup ancestors for ActiveModel.
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# File 'activerecord/lib/active_record/base.rb', line 806 def lookup_ancestors #:nodoc: klass = self classes = [klass] return classes if klass == ActiveRecord::Base while klass != klass.base_class classes << klass = klass.superclass end classes end |
.mysql2_connection(config) ⇒ Object
Establishes a connection to the database that’s used by all Active Record objects.
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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 9 def self.mysql2_connection(config) config[:username] = 'root' if config[:username].nil? if Mysql2::Client.const_defined? :FOUND_ROWS config[:flags] = Mysql2::Client::FOUND_ROWS end client = Mysql2::Client.new(config.symbolize_keys) = [config[:host], config[:username], config[:password], config[:database], config[:port], config[:socket], 0] ConnectionAdapters::Mysql2Adapter.new(client, logger, , config) end |
.mysql_connection(config) ⇒ Object
Establishes a connection to the database that’s used by all Active Record objects.
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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 25 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 database = config[:database] mysql = Mysql.init mysql.ssl_set(config[:sslkey], config[:sslcert], config[:sslca], config[:sslcapath], config[:sslcipher]) if config[:sslca] || config[:sslkey] default_flags = Mysql.const_defined?(:CLIENT_MULTI_RESULTS) ? Mysql::CLIENT_MULTI_RESULTS : 0 default_flags |= Mysql::CLIENT_FOUND_ROWS if Mysql.const_defined?(:CLIENT_FOUND_ROWS) = [host, username, password, database, port, socket, default_flags] ConnectionAdapters::MysqlAdapter.new(mysql, logger, , 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 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 13 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.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 |
.quote_value(value, column = nil) ⇒ Object
:nodoc:
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# File 'activerecord/lib/active_record/base.rb', line 850 def quote_value(value, column = nil) #:nodoc: connection.quote(value,column) end |
.quoted_table_name ⇒ Object
Returns a quoted version of the table name, used to construct SQL statements.
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# File 'activerecord/lib/active_record/base.rb', line 619 def quoted_table_name @quoted_table_name ||= connection.quote_table_name(table_name) end |
.readonly_attributes ⇒ Object
Returns an array of all the attributes that have been specified as readonly.
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# File 'activerecord/lib/active_record/base.rb', line 538 def readonly_attributes self._attr_readonly end |
.remove_connection(klass = self) ⇒ Object
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# File 'activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb', line 115 def remove_connection(klass = self) connection_handler.remove_connection(klass) end |
.reset_column_information ⇒ Object
Resets all the cached information about columns, which will cause them to be reloaded on the next request.
The most common usage pattern for this method is probably in a migration, when just after creating a table you want to populate it with some default values, eg:
class CreateJobLevels < ActiveRecord::Migration
def self.up
create_table :job_levels do |t|
t.integer :id
t.string :name
t.
end
JobLevel.reset_column_information
%w{assistant executive manager director}.each do |type|
JobLevel.create(:name => type)
end
end
def self.down
drop_table :job_levels
end
end
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# File 'activerecord/lib/active_record/base.rb', line 777 def reset_column_information connection.clear_cache! undefine_attribute_methods connection_pool.clear_table_cache!(table_name) if table_exists? @column_names = @content_columns = @dynamic_methods_hash = @inheritance_column = nil @arel_engine = @relation = nil end |
.reset_sequence_name ⇒ Object
:nodoc:
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# File 'activerecord/lib/active_record/base.rb', line 646 def reset_sequence_name #:nodoc: default = connection.default_sequence_name(table_name, primary_key) set_sequence_name(default) default end |
.reset_table_name ⇒ Object
Computes the table name, (re)sets it internally, and returns it.
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# File 'activerecord/lib/active_record/base.rb', line 624 def reset_table_name #:nodoc: return if abstract_class? self.table_name = compute_table_name end |
.respond_to?(method_id, include_private = false) ⇒ Boolean
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# File 'activerecord/lib/active_record/base.rb', line 890 def respond_to?(method_id, include_private = false) if match = DynamicFinderMatch.match(method_id) return true if all_attributes_exists?(match.attribute_names) elsif match = DynamicScopeMatch.match(method_id) return true if all_attributes_exists?(match.attribute_names) end super end |
.retrieve_connection ⇒ Object
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# File 'activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb', line 106 def retrieve_connection connection_handler.retrieve_connection(self) 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 'activerecord/lib/active_record/base.rb', line 855 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 'activerecord/lib/active_record/base.rb', line 642 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.
Parameters
-
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 < ActiveRecord::Base
serialize :preferences
end
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# File 'activerecord/lib/active_record/base.rb', line 557 def serialize(attr_name, class_name = Object) coder = if [:load, :dump].all? { |x| class_name.respond_to?(x) } class_name else Coders::YAMLColumn.new(class_name) end # merge new serialized attribute and create new hash to ensure that each class in inheritance hierarchy # has its own hash of own serialized attributes self.serialized_attributes = serialized_attributes.merge(attr_name.to_s => coder) 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 'activerecord/lib/active_record/base.rb', line 677 def set_inheritance_column(value = nil, &block) define_attr_method :inheritance_column, 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 'activerecord/lib/active_record/base.rb', line 696 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. If the value is nil or false then the value returned by the given block is used.
class Project < ActiveRecord::Base
set_table_name "project"
end
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# File 'activerecord/lib/active_record/base.rb', line 658 def set_table_name(value = nil, &block) @quoted_table_name = nil define_attr_method :table_name, value, &block @arel_table = nil @arel_table = Arel::Table.new(table_name, arel_engine) @relation = Relation.new(self, arel_table) end |
.sqlite3_connection(config) ⇒ Object
sqlite3 adapter reuses sqlite_connection.
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# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 9 def self.sqlite3_connection(config) # :nodoc: # Require database. unless config[:database] raise ArgumentError, "No database file specified. Missing argument: database" end # Allow database path relative to Rails.root, but only if # the database path is not the special path that tells # Sqlite to build a database only in memory. if defined?(Rails.root) && ':memory:' != config[:database] config[:database] = File.(config[:database], Rails.root) end unless 'sqlite3' == config[:adapter] raise ArgumentError, 'adapter name should be "sqlite3"' end db = SQLite3::Database.new( config[:database], :results_as_hash => true ) db.busy_timeout(config[:timeout]) if config[:timeout] ConnectionAdapters::SQLite3Adapter.new(db, logger, config) end |
.sti_name ⇒ Object
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# File 'activerecord/lib/active_record/base.rb', line 900 def sti_name store_full_sti_class ? name : name.demodulize end |
.symbolized_base_class ⇒ Object
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# File 'activerecord/lib/active_record/base.rb', line 864 def symbolized_base_class @symbolized_base_class ||= base_class.to_s.to_sym end |
.symbolized_sti_name ⇒ Object
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# File 'activerecord/lib/active_record/base.rb', line 868 def symbolized_sti_name @symbolized_sti_name ||= sti_name.present? ? sti_name.to_sym : symbolized_base_class end |
.table_exists? ⇒ Boolean
Indicates whether the table associated with this class exists
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# File 'activerecord/lib/active_record/base.rb', line 702 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 'activerecord/lib/active_record/base.rb', line 614 def table_name reset_table_name end |
.unscoped ⇒ Object
Returns a scope for this class without taking into account the default_scope.
class Post < ActiveRecord::Base
def self.default_scope
where :published => true
end
end
Post.all # Fires "SELECT * FROM posts WHERE published = true"
Post.unscoped.all # Fires "SELECT * FROM posts"
This method also accepts a block meaning that all queries inside the block will not use the default_scope:
Post.unscoped {
Post.limit(10) # Fires "SELECT * FROM posts LIMIT 10"
}
It is recommended to use block form of unscoped because chaining unscoped with scope
does not work. Assuming that published
is a scope
following two statements are same.
Post.unscoped.published Post.published
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# File 'activerecord/lib/active_record/base.rb', line 941 def unscoped #:nodoc: block_given? ? relation.scoping { yield } : relation end |
Instance Method Details
#<=>(other_object) ⇒ Object
Allows sort on objects
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# File 'activerecord/lib/active_record/base.rb', line 1836 def <=>(other_object) if other_object.is_a?(self.class) self.to_key <=> other_object.to_key else nil end end |
#==(comparison_object) ⇒ Object Also known as: eql?
Returns true if comparison_object
is the same exact object, or comparison_object
is of the same type and self
has an ID and it is equal to comparison_object.id
.
Note that new records are different from any other record by definition, unless the other record is the receiver itself. Besides, if you fetch existing records with select
and leave the ID out, you’re on your own, this predicate will return false.
Note also that destroying a record preserves its ID in the model instance, so deleted models are still comparable.
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# File 'activerecord/lib/active_record/base.rb', line 1811 def ==(comparison_object) super || comparison_object.instance_of?(self.class) && id.present? && comparison_object.id == id end |
#assign_attributes(new_attributes, options = {}) ⇒ Object
Allows you to set all the attributes for a particular mass-assignment security role by passing in a hash of attributes with keys matching the attribute names (which again matches the column names) and the role name using the :as option.
To bypass mass-assignment security you can use the :without_protection => true option.
class User < ActiveRecord::Base
attr_accessible :name
attr_accessible :name, :is_admin, :as => :admin
end
user = User.new
user.assign_attributes({ :name => 'Josh', :is_admin => true })
user.name # => "Josh"
user.is_admin? # => false
user = User.new
user.assign_attributes({ :name => 'Josh', :is_admin => true }, :as => :admin)
user.name # => "Josh"
user.is_admin? # => true
user = User.new
user.assign_attributes({ :name => 'Josh', :is_admin => true }, :without_protection => true)
user.name # => "Josh"
user.is_admin? # => true
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# File 'activerecord/lib/active_record/base.rb', line 1736 def assign_attributes(new_attributes, = {}) return unless new_attributes attributes = new_attributes.stringify_keys multi_parameter_attributes = [] @mass_assignment_options = unless [:without_protection] attributes = sanitize_for_mass_assignment(attributes, mass_assignment_role) end attributes.each do |k, v| if k.include?("(") multi_parameter_attributes << [ k, v ] elsif respond_to?("#{k}=") send("#{k}=", v) else raise(UnknownAttributeError, "unknown attribute: #{k}") end end @mass_assignment_options = nil assign_multiparameter_attributes(multi_parameter_attributes) end |
#attribute_for_inspect(attr_name) ⇒ Object
Returns an #inspect
-like string for the value of the attribute attr_name
. String attributes are truncated upto 50 characters, and Date and Time attributes are returned in the :db
format. Other attributes return the value of #inspect
without modification.
person = Person.create!(:name => "David Heinemeier Hansson " * 3)
person.attribute_for_inspect(:name)
# => '"David Heinemeier Hansson David Heinemeier Hansson D..."'
person.attribute_for_inspect(:created_at)
# => '"2009-01-12 04:48:57"'
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# File 'activerecord/lib/active_record/base.rb', line 1779 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.
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# File 'activerecord/lib/active_record/base.rb', line 1672 def attribute_names @attributes.keys 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 'activerecord/lib/active_record/base.rb', line 1793 def attribute_present?(attribute) !_read_attribute(attribute).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 'activerecord/lib/active_record/base.rb', line 1762 def attributes Hash[@attributes.map { |name, _| [name, read_attribute(name)] }] end |
#attributes=(new_attributes, guard_protected_attributes = nil) ⇒ 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).
If any attributes are protected by either attr_protected
or attr_accessible
then only settable attributes will be assigned.
The guard_protected_attributes
argument is now deprecated, use the assign_attributes
method if you want to bypass mass-assignment security.
class User < ActiveRecord::Base
attr_protected :is_admin
end
user = User.new
user.attributes = { :username => 'Phusion', :is_admin => true }
user.username # => "Phusion"
user.is_admin? # => false
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# File 'activerecord/lib/active_record/base.rb', line 1693 def attributes=(new_attributes, guard_protected_attributes = nil) unless guard_protected_attributes.nil? = "the use of 'guard_protected_attributes' will be removed from the next minor release of rails, " + "if you want to bypass mass-assignment security then look into using assign_attributes" ActiveSupport::Deprecation.warn() end return unless new_attributes.is_a?(Hash) if guard_protected_attributes == false assign_attributes(new_attributes, :without_protection => true) else assign_attributes(new_attributes) 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 'activerecord/lib/active_record/base.rb', line 1650 def cache_key case when new_record? "#{self.class.model_name.cache_key}/new" when = self[:updated_at] = .utc.to_s(:number) "#{self.class.model_name.cache_key}/#{id}-#{}" else "#{self.class.model_name.cache_key}/#{id}" end end |
#column_for_attribute(name) ⇒ Object
Returns the column object for the named attribute.
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# File 'activerecord/lib/active_record/base.rb', line 1798 def column_for_attribute(name) self.class.columns_hash[name.to_s] end |
#configurations ⇒ Object
:singleton-method: Contains the database configuration - as is typically stored in config/database.yml - as a Hash.
For example, the following database.yml…
development:
adapter: sqlite3
database: db/development.sqlite3
production:
adapter: sqlite3
database: db/production.sqlite3
…would result in ActiveRecord::Base.configurations to look like this:
{
'development' => {
'adapter' => 'sqlite3',
'database' => 'db/development.sqlite3'
},
'production' => {
'adapter' => 'sqlite3',
'database' => 'db/production.sqlite3'
}
}
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# File 'activerecord/lib/active_record/base.rb', line 359 cattr_accessor :configurations, :instance_writer => false |
#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 'activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb', line 19 def connection self.class.connection end |
#connection_handler ⇒ Object
:singleton-method: The connection handler
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# File 'activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb', line 13 class_attribute :connection_handler, :instance_writer => false |
#default_timezone ⇒ Object
:singleton-method: Determines whether to use Time.local (using :local) or Time.utc (using :utc) when pulling dates and times from the database. This is set to :local by default.
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# File 'activerecord/lib/active_record/base.rb', line 404 cattr_accessor :default_timezone, :instance_writer => false |
#dup ⇒ Object
:nodoc:
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# File 'activerecord/lib/active_record/base.rb', line 1846 def dup # :nodoc: copy = super copy.initialize_dup(self) copy end |
#encode_with(coder) ⇒ Object
Populate coder
with attributes about this record that should be serialized. The structure of coder
defined in this method is guaranteed to match the structure of coder
passed to the init_with
method.
Example:
class Post < ActiveRecord::Base
end
coder = {}
Post.new.encode_with(coder)
coder # => { 'id' => nil, ... }
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# File 'activerecord/lib/active_record/base.rb', line 1585 def encode_with(coder) coder['attributes'] = attributes end |
#freeze ⇒ Object
Freeze the attributes hash such that associations are still accessible, even on destroyed records.
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# File 'activerecord/lib/active_record/base.rb', line 1826 def freeze @attributes.freeze; self end |
#frozen? ⇒ Boolean
Returns true
if the attributes hash has been frozen.
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# File 'activerecord/lib/active_record/base.rb', line 1831 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 'activerecord/lib/active_record/base.rb', line 1667 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 'activerecord/lib/active_record/base.rb', line 1821 def hash id.hash end |
#init_with(coder) ⇒ Object
Initialize an empty model object from coder
. coder
must contain the attributes necessary for initializing an empty model object. For example:
class Post < ActiveRecord::Base
end
post = Post.allocate
post.init_with('attributes' => { 'title' => 'hello world' })
post.title # => 'hello world'
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# File 'activerecord/lib/active_record/base.rb', line 1599 def init_with(coder) @attributes = coder['attributes'] @relation = nil set_serialized_attributes @attributes_cache, @previously_changed, @changed_attributes = {}, {}, {} @association_cache = {} @aggregation_cache = {} @readonly = @destroyed = @marked_for_destruction = false @new_record = false run_callbacks :find run_callbacks :initialize self end |
#initialize_dup(other) ⇒ Object
Duped objects have no id assigned and are treated as new records. Note that this is a “shallow” copy as it copies the object’s attributes only, not its associations. The extent of a “deep” copy is application specific and is therefore left to the application to implement according to its need. The dup method does not preserve the timestamps (created|updated)_(at|on).
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# File 'activerecord/lib/active_record/base.rb', line 1859 def initialize_dup(other) cloned_attributes = other.clone_attributes(:read_attribute_before_type_cast) cloned_attributes.delete(self.class.primary_key) @attributes = cloned_attributes _run_after_initialize_callbacks if respond_to?(:_run_after_initialize_callbacks) @changed_attributes = {} attributes_from_column_definition.each do |attr, orig_value| @changed_attributes[attr] = orig_value if field_changed?(attr, orig_value, @attributes[attr]) end @aggregation_cache = {} @association_cache = {} @attributes_cache = {} @new_record = true ensure_proper_type populate_with_current_scope_attributes end |
#inspect ⇒ Object
Returns the contents of the record as a nicely formatted string.
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# File 'activerecord/lib/active_record/base.rb', line 1894 def inspect attributes_as_nice_string = self.class.column_names.collect { |name| if has_attribute?(name) "#{name}: #{attribute_for_inspect(name)}" end }.compact.join(", ") "#<#{self.class} #{attributes_as_nice_string}>" end |
#logger ⇒ Object
:singleton-method: Accepts a logger conforming to the interface of Log4r or the default Ruby 1.8+ Logger class, which is then passed on to any new database connections made and which can be retrieved on both a class and instance level by calling logger
.
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# File 'activerecord/lib/active_record/base.rb', line 330 cattr_accessor :logger, :instance_writer => false |
#pluralize_table_names ⇒ Object
:singleton-method: Indicates whether table names should be the pluralized versions of the corresponding class names. If true, the default table name for a Product class will be products
. If false, it would just be product
. See table_name for the full rules on table/class naming. This is true, by default.
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# File 'activerecord/lib/active_record/base.rb', line 397 class_attribute :pluralize_table_names, :instance_writer => false |
#primary_key_prefix_type ⇒ Object
:singleton-method: Accessor for the prefix type that will be prepended to every primary key column name. The options are :table_name and :table_name_with_underscore. If the first is specified, the Product class will look for “productid” instead of “id” as the primary column. If the latter is specified, the Product class will look for “product_id” instead of “id”. Remember that this is a global setting for all Active Records.
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# File 'activerecord/lib/active_record/base.rb', line 369 cattr_accessor :primary_key_prefix_type, :instance_writer => false |
#quoted_id ⇒ Object
:nodoc:
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# File 'activerecord/lib/active_record/base.rb', line 1662 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 'activerecord/lib/active_record/base.rb', line 1889 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 'activerecord/lib/active_record/base.rb', line 1884 def readonly? @readonly end |
#schema_format ⇒ Object
:singleton-method: Specifies the format to use when dumping the database schema with Rails’ Rakefile. If :sql, the schema is dumped as (potentially database- specific) SQL statements. If :ruby, the schema is dumped as an ActiveRecord::Schema file which can be loaded into any database that supports migrations. Use :ruby if you want to have different database adapters for, e.g., your development and test environments.
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# File 'activerecord/lib/active_record/base.rb', line 415 cattr_accessor :schema_format , :instance_writer => false |
#table_name_prefix ⇒ Object
:singleton-method: Accessor for the name of the prefix string to prepend to every table name. So if set to “basecamp_”, all table names will be named like “basecamp_projects”, “basecamp_people”, etc. This is a convenient way of creating a namespace for tables in a shared database. By default, the prefix is the empty string.
If you are organising your models within modules you can add a prefix to the models within a namespace by defining a singleton method in the parent module called table_name_prefix which returns your chosen prefix.
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# File 'activerecord/lib/active_record/base.rb', line 382 class_attribute :table_name_prefix, :instance_writer => false |
#table_name_suffix ⇒ Object
:singleton-method: Works like table_name_prefix
, but appends instead of prepends (set to “_basecamp” gives “projects_basecamp”, “people_basecamp”). By default, the suffix is the empty string.
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# File 'activerecord/lib/active_record/base.rb', line 389 class_attribute :table_name_suffix, :instance_writer => false |
#timestamped_migrations ⇒ Object
:singleton-method: Specify whether or not to use timestamps for migration versions
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# File 'activerecord/lib/active_record/base.rb', line 421 cattr_accessor :timestamped_migrations , :instance_writer => false |
#to_param ⇒ Object
Returns a String, which Action Pack uses for constructing an URL to this object. The default implementation returns this record’s id as a String, or nil if this record’s unsaved.
For example, suppose that you have a User model, and that you have a resources :users
route. Normally, user_path
will construct a path with the user object’s ‘id’ in it:
user = User.find_by_name('Phusion')
user_path(user) # => "/users/1"
You can override to_param
in your model to make user_path
construct a path using the user’s name instead of the user’s id:
class User < ActiveRecord::Base
def to_param # overridden
name
end
end
user = User.find_by_name('Phusion')
user_path(user) # => "/users/Phusion"
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# File 'activerecord/lib/active_record/base.rb', line 1638 def to_param # We can't use alias_method here, because method 'id' optimizes itself on the fly. id && id.to_s # Be sure to stringify the id for routes end |