Class: ActiveRecord::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/activerecord-import/synchronize.rb,
lib/activerecord-import/import.rb

Overview

:nodoc:

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.import(*args) ⇒ Object

Imports a collection of values to the database.

This is more efficient than using ActiveRecord::Base#create or ActiveRecord::Base#save multiple times. This method works well if you want to create more than one record at a time and do not care about having ActiveRecord objects returned for each record inserted.

This can be used with or without validations. It does not utilize the ActiveRecord::Callbacks during creation/modification while performing the import.

Usage

Model.import array_of_models
Model.import column_names, array_of_models
Model.import array_of_hash_objects
Model.import column_names, array_of_hash_objects
Model.import column_names, array_of_values
Model.import column_names, array_of_values, options

Model.import array_of_models

With this form you can call import passing in an array of model objects that you want updated.

Model.import column_names, array_of_values

The first parameter column_names is an array of symbols or strings which specify the columns that you want to update.

The second parameter, array_of_values, is an array of arrays. Each subarray is a single set of values for a new record. The order of values in each subarray should match up to the order of the column_names.

Model.import column_names, array_of_values, options

The first two parameters are the same as the above form. The third parameter, options, is a hash. This is optional. Please see below for what options are available.

Options

  • validate - true|false, tells import whether or not to use

    ActiveRecord validations. Validations are enforced by default.

  • ignore - true|false, an alias for on_duplicate_key_ignore.

  • on_duplicate_key_ignore - true|false, tells import to discard

    records that contain duplicate keys. For Postgres 9.5+ it adds
ON CONFLICT DO NOTHING, for MySQL it uses INSERT IGNORE, and for
SQLite it uses INSERT OR IGNORE. Cannot be enabled on a
recursive import. For database adapters that normally support
setting primary keys on imported objects, this option prevents
that from occurring.

  • on_duplicate_key_update - an Array or Hash, tells import to

    use MySQL's ON DUPLICATE KEY UPDATE or Postgres 9.5+ ON CONFLICT
DO UPDATE ability. See On Duplicate Key Update below.

  • synchronize - an array of ActiveRecord instances for the model that you are currently importing data into. This synchronizes existing model instances in memory with updates from the import.

  • timestamps - true|false, tells import to not add timestamps (if false) even if record timestamps is disabled in ActiveRecord::Base

  • recursive - true|false, tells import to import all has_many/has_one associations if the adapter supports setting the primary keys of the newly imported objects. PostgreSQL only.

  • batch_size - an integer value to specify the max number of records to include per insert. Defaults to the total number of records to import.

Examples

class BlogPost < ActiveRecord::Base ; end

# Example using array of model objects
posts = [ BlogPost.new author_name: 'Zach Dennis', title: 'AREXT',
          BlogPost.new author_name: 'Zach Dennis', title: 'AREXT2',
          BlogPost.new author_name: 'Zach Dennis', title: 'AREXT3' ]
BlogPost.import posts

# Example using array_of_hash_objects
values = [ {author_name: 'zdennis', title: 'test post'} ], [ {author_name: 'jdoe', title: 'another test post'} ] ]
BlogPost.import values

# Example using column_names and array_of_hash_objects
columns = [ :author_name, :title ]
values = [ {author_name: 'zdennis', title: 'test post'} ], [ {author_name: 'jdoe', title: 'another test post'} ] ]
BlogPost.import columns, values

# Example using column_names and array_of_values
columns = [ :author_name, :title ]
values = [ [ 'zdennis', 'test post' ], [ 'jdoe', 'another test post' ] ]
BlogPost.import columns, values

# Example using column_names, array_of_value and options
columns = [ :author_name, :title ]
values = [ [ 'zdennis', 'test post' ], [ 'jdoe', 'another test post' ] ]
BlogPost.import( columns, values, validate: false  )

# Example synchronizing existing instances in memory
post = BlogPost.where(author_name: 'zdennis').first
puts post.author_name # => 'zdennis'
columns = [ :author_name, :title ]
values = [ [ 'yoda', 'test post' ] ]
BlogPost.import posts, synchronize: [ post ]
puts post.author_name # => 'yoda'

# Example synchronizing unsaved/new instances in memory by using a uniqued imported field
posts = [BlogPost.new(title: "Foo"), BlogPost.new(title: "Bar")]
BlogPost.import posts, synchronize: posts, synchronize_keys: [:title]
puts posts.first.persisted? # => true

On Duplicate Key Update (MySQL)

The :on_duplicate_key_update option can be either an Array or a Hash.

Using an Array

The :on_duplicate_key_update option can be an array of column names. The column names are the only fields that are updated if a duplicate record is found. Below is an example:

BlogPost.import columns, values, on_duplicate_key_update: [ :date_modified, :content, :author ]

Using A Hash

The :on_duplicate_key_update option can be a hash of column names to model attribute name mappings. This gives you finer grained control over what fields are updated with what attributes on your model. Below is an example:

BlogPost.import columns, attributes, on_duplicate_key_update: { title: :title }

On Duplicate Key Update (Postgres 9.5+)

The :on_duplicate_key_update option can be an Array or a Hash with up to three attributes, :conflict_target (and optionally :index_predicate) or :constraint_name, and :columns.

Using an Array

The :on_duplicate_key_update option can be an array of column names. This option only handles inserts that conflict with the primary key. If a table does not have a primary key, this will not work. The column names are the only fields that are updated if a duplicate record is found. Below is an example:

BlogPost.import columns, values, on_duplicate_key_update: [ :date_modified, :content, :author ]

Using a Hash

The :on_duplicate_key_update option can be a hash with up to three attributes, :conflict_target (and optionally :index_predicate) or :constraint_name, and :columns. Unlike MySQL, Postgres requires the conflicting constraint to be explicitly specified. Using this option allows you to specify a constraint other than the primary key.

:conflict_target

The :conflict_target attribute specifies the columns that make up the conflicting unique constraint and can be a single column or an array of column names. This attribute is ignored if :constraint_name is included, but it is the preferred method of identifying a constraint. It will default to the primary key. Below is an example:

BlogPost.import columns, values, on_duplicate_key_update: { conflict_target: [ :author_id, :slug ], columns: [ :date_modified ] }
:index_predicate

The :index_predicate attribute optionally specifies a WHERE condition on :conflict_target, which is required for matching against partial indexes. This attribute is ignored if :constraint_name is included. Below is an example:

BlogPost.import columns, values, on_duplicate_key_update: { conflict_target: [ :author_id, :slug ], index_predicate: 'status <> 0', columns: [ :date_modified ] }
:constraint_name

The :constraint_name attribute explicitly identifies the conflicting unique index by name. Postgres documentation discourages using this method of identifying an index unless absolutely necessary. Below is an example:

BlogPost.import columns, values, on_duplicate_key_update: { constraint_name: :blog_posts_pkey, columns: [ :date_modified ] }
:columns

The :columns attribute can be either an Array or a Hash.

Using an Array

The :columns attribute can be an array of column names. The column names are the only fields that are updated if a duplicate record is found. Below is an example:

BlogPost.import columns, values, on_duplicate_key_update: { conflict_target: :slug, columns: [ :date_modified, :content, :author ] }
Using a Hash

The :columns option can be a hash of column names to model attribute name mappings. This gives you finer grained control over what fields are updated with what attributes on your model. Below is an example:

BlogPost.import columns, attributes, on_duplicate_key_update: { conflict_target: :slug, columns: { title: :title } }

Returns

This returns an object which responds to failed_instances and num_inserts.

  • failed_instances - an array of objects that fails validation and were not committed to the database. An empty array if no validation is performed.

  • num_inserts - the number of insert statements it took to import the data

  • ids - the primary keys of the imported ids if the adapter supports it, otherwise an empty array.



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# File 'lib/activerecord-import/import.rb', line 378

def import(*args)
  if args.first.is_a?( Array ) && args.first.first.is_a?(ActiveRecord::Base)
    options = {}
    options.merge!( args.pop ) if args.last.is_a?(Hash)

    models = args.first
    import_helper(models, options)
  else
    import_helper(*args)
  end
end

.import!(*args) ⇒ Object

Imports a collection of values if all values are valid. Import fails at the first encountered validation error and raises ActiveRecord::RecordInvalid with the failed instance.



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# File 'lib/activerecord-import/import.rb', line 393

def import!(*args)
  options = args.last.is_a?( Hash ) ? args.pop : {}
  options[:validate] = true
  options[:raise_error] = true

  import(*args, options)
end

.import_helper(*args) ⇒ Object 



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# File 'lib/activerecord-import/import.rb', line 401

def import_helper( *args )
  options = { validate: true, timestamps: true }
  options.merge!( args.pop ) if args.last.is_a? Hash
  # making sure that current model's primary key is used
  options[:primary_key] = primary_key

  # Don't modify incoming arguments
  if options[:on_duplicate_key_update] && options[:on_duplicate_key_update].duplicable?
    options[:on_duplicate_key_update] = options[:on_duplicate_key_update].dup
  end

  is_validating = options[:validate]
  is_validating = true unless options[:validate_with_context].nil?

  # assume array of model objects
  if args.last.is_a?( Array ) && args.last.first.is_a?(ActiveRecord::Base)
    if args.length == 2
      models = args.last
      column_names = args.first.dup
    else
      models = args.first
      column_names = self.column_names.dup
    end

    if models.first.id.nil? && column_names.include?(primary_key) && columns_hash[primary_key].type == :uuid
      column_names.delete(primary_key)
    end

    stored_attrs = respond_to?(:stored_attributes) ? stored_attributes : {}
    default_values = column_defaults

    array_of_attributes = models.map do |model|
      column_names.map do |name|
        is_stored_attr = stored_attrs.any? && stored_attrs.key?(name.to_sym)
        if is_stored_attr || default_values[name].is_a?(Hash)
          model.read_attribute(name.to_s)
        else
          model.read_attribute_before_type_cast(name.to_s)
        end
      end
    end
    # supports array of hash objects
  elsif args.last.is_a?( Array ) && args.last.first.is_a?(Hash)
    if args.length == 2
      array_of_hashes = args.last
      column_names = args.first.dup
    else
      array_of_hashes = args.first
      column_names = array_of_hashes.first.keys
    end

    array_of_attributes = array_of_hashes.map do |h|
      column_names.map do |key|
        h[key]
      end
    end
    # supports empty array
  elsif args.last.is_a?( Array ) && args.last.empty?
    return ActiveRecord::Import::Result.new([], 0, [])
    # supports 2-element array and array
  elsif args.size == 2 && args.first.is_a?( Array ) && args.last.is_a?( Array )

    unless args.last.first.is_a?(Array)
      raise ArgumentError, "Last argument should be a two dimensional array '[[]]'. First element in array was a #{args.last.first.class}"
    end

    column_names, array_of_attributes = args

    # dup the passed args so we don't modify unintentionally
    column_names = column_names.dup
    array_of_attributes = array_of_attributes.map(&:dup)
  else
    raise ArgumentError, "Invalid arguments!"
  end

  # Force the primary key col into the insert if it's not
  # on the list and we are using a sequence and stuff a nil
  # value for it into each row so the sequencer will fire later
  symbolized_column_names = Array(column_names).map(&:to_sym)
  symbolized_primary_key = Array(primary_key).map(&:to_sym)

  if !symbolized_primary_key.to_set.subset?(symbolized_column_names.to_set) && connection.prefetch_primary_key? && sequence_name
    column_count = column_names.size
    column_names.concat(primary_key).uniq!
    columns_added = column_names.size - column_count
    new_fields = Array.new(columns_added)
    array_of_attributes.each { |a| a.concat(new_fields) }
  end

  timestamps = {}

  # record timestamps unless disabled in ActiveRecord::Base
  if record_timestamps && options.delete( :timestamps )
    timestamps = add_special_rails_stamps column_names, array_of_attributes, options
  end

  return_obj = if is_validating
    if models
      import_with_validations( column_names, array_of_attributes, options ) do |validator, failed|
        models.each_with_index do |model, i|
          model = model.dup if options[:recursive]
          next if validator.valid_model? model
          raise(ActiveRecord::RecordInvalid, model) if options[:raise_error]
          array_of_attributes[i] = nil
          failed << model
        end
      end
    else
      import_with_validations( column_names, array_of_attributes, options )
    end
  else
    (num_inserts, ids) = import_without_validations_or_callbacks( column_names, array_of_attributes, options )
    ActiveRecord::Import::Result.new([], num_inserts, ids)
  end

  if options[:synchronize]
    sync_keys = options[:synchronize_keys] || [primary_key]
    synchronize( options[:synchronize], sync_keys)
  end
  return_obj.num_inserts = 0 if return_obj.num_inserts.nil?

  # if we have ids, then set the id on the models and mark the models as clean.
  if models && support_setting_primary_key_of_imported_objects?
    if options[:recursive] || !(options[:ignore] || options[:on_duplicate_key_ignore])
      set_attributes_and_mark_clean(models, return_obj, timestamps)
    end

    # if there are auto-save associations on the models we imported that are new, import them as well
    import_associations(models, options.dup) if options[:recursive]
  end

  return_obj
end

.import_with_validations(column_names, array_of_attributes, options = {}) ⇒ Object

Imports the passed in column_names and array_of_attributes given the passed in options Hash with validations. Returns an object with the methods failed_instances and num_inserts. failed_instances is an array of instances that failed validations. num_inserts is the number of inserts it took to import the data. See ActiveRecord::Base.import for more information on column_names, array_of_attributes and options.



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# File 'lib/activerecord-import/import.rb', line 542

def import_with_validations( column_names, array_of_attributes, options = {} )
  failed_instances = []

  validator = ActiveRecord::Import::Validator.new(options)

  if block_given?
    yield validator, failed_instances
  else
    # create instances for each of our column/value sets
    arr = validations_array_for_column_names_and_attributes( column_names, array_of_attributes )

    # keep track of the instance and the position it is currently at. if this fails
    # validation we'll use the index to remove it from the array_of_attributes
    model = new
    arr.each_with_index do |hsh, i|
      hsh.each_pair { |k, v| model[k] = v }
      next if validator.valid_model? model
      raise(ActiveRecord::RecordInvalid, model) if options[:raise_error]
      array_of_attributes[i] = nil
      failure = model.dup
      failure.errors.send(:initialize_dup, model.errors)
      failed_instances << failure
    end
  end

  array_of_attributes.compact!

  num_inserts, ids = if array_of_attributes.empty? || options[:all_or_none] && failed_instances.any?
    [0, []]
  else
    import_without_validations_or_callbacks( column_names, array_of_attributes, options )
  end
  ActiveRecord::Import::Result.new(failed_instances, num_inserts, ids)
end

.import_without_validations_or_callbacks(column_names, array_of_attributes, options = {}) ⇒ Object

Imports the passed in column_names and array_of_attributes given the passed in options Hash. This will return the number of insert operations it took to create these records without validations or callbacks. See ActiveRecord::Base.import for more information on column_names, +array_of_attributes_ and options.



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# File 'lib/activerecord-import/import.rb', line 583

def import_without_validations_or_callbacks( column_names, array_of_attributes, options = {} )
  column_names = column_names.map(&:to_sym)
  scope_columns, scope_values = scope_attributes.to_a.transpose

  unless scope_columns.blank?
    scope_columns.zip(scope_values).each do |name, value|
      name_as_sym = name.to_sym
      next if column_names.include?(name_as_sym)

      is_sti = (name_as_sym == inheritance_column.to_sym && self < base_class)
      value = value.first if is_sti

      column_names << name_as_sym
      array_of_attributes.each { |attrs| attrs << value }
    end
  end

  columns = column_names.each_with_index.map do |name, i|
    column = columns_hash[name.to_s]

    raise ActiveRecord::Import::MissingColumnError.new(name.to_s, i) if column.nil?

    column
  end

  columns_sql = "(#{column_names.map { |name| connection.quote_column_name(name) }.join(',')})"
  pre_sql_statements = connection.pre_sql_statements( options )
  insert_sql = ['INSERT', pre_sql_statements, "INTO #{quoted_table_name} #{columns_sql} VALUES "]
  insert_sql = insert_sql.flatten.join(' ')
  values_sql = values_sql_for_columns_and_attributes(columns, array_of_attributes)

  number_inserted = 0
  ids = []
  if supports_import?
    # generate the sql
    post_sql_statements = connection.post_sql_statements( quoted_table_name, options )

    batch_size = options[:batch_size] || values_sql.size
    values_sql.each_slice(batch_size) do |batch_values|
      # perform the inserts
      result = connection.insert_many( [insert_sql, post_sql_statements].flatten,
        batch_values,
        options,
        "#{self.class.name} Create Many Without Validations Or Callbacks" )
      number_inserted += result[0]
      ids += result[1]
    end
  else
    transaction(requires_new: true) do
      values_sql.each do |values|
        ids << connection.insert(insert_sql + values)
        number_inserted += 1
      end
    end
  end
  [number_inserted, ids]
end

.support_setting_primary_key_of_imported_objects? ⇒ Boolean

returns true if the current database connection adapter supports setting the primary key of bulk imported models, otherwise returns false

Returns:

  • (Boolean) 


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# File 'lib/activerecord-import/import.rb', line 170

def support_setting_primary_key_of_imported_objects?
  connection.respond_to?(:support_setting_primary_key_of_imported_objects?) && connection.support_setting_primary_key_of_imported_objects?
end

.supports_import?(*args) ⇒ Boolean

Returns true if the current database connection adapter supports import functionality, otherwise returns false.

Returns:

  • (Boolean) 


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# File 'lib/activerecord-import/import.rb', line 156

def supports_import?(*args)
  connection.respond_to?(:supports_import?) && connection.supports_import?(*args)
end

.supports_on_duplicate_key_update? ⇒ Boolean

Returns true if the current database connection adapter supports on duplicate key update functionality, otherwise returns false.

Returns:

  • (Boolean) 


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# File 'lib/activerecord-import/import.rb', line 163

def supports_on_duplicate_key_update?
  connection.supports_on_duplicate_key_update?
end

.synchronize(instances, keys = [primary_key]) ⇒ Object

Synchronizes the passed in ActiveRecord instances with data from the database. This is like calling reload on an individual ActiveRecord instance but it is intended for use on multiple instances.

This uses one query for all instance updates and then updates existing instances rather sending one query for each instance

Examples

# Synchronizing existing models by matching on the primary key field posts = Post.where(author: “Zach”).first <.. out of system changes occur to change author name from Zach to Zachary..> Post.synchronize posts posts.first.author # => “Zachary” instead of Zach

# Synchronizing using custom key fields posts = Post.where(author: “Zach”).first <.. out of system changes occur to change the address of author ‘Zach’ to 1245 Foo Ln ..> Post.synchronize posts, [:name] # queries on the :name column and not the :id column posts.first.address # => “1245 Foo Ln” instead of whatever it was



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# File 'lib/activerecord-import/synchronize.rb', line 23

def self.synchronize(instances, keys = [primary_key])
  return if instances.empty?

  conditions = {}

  key_values = keys.map { |key| instances.map(&key.to_sym) }
  keys.zip(key_values).each { |key, values| conditions[key] = values }
  order = keys.map { |key| "#{key} ASC" }.join(",")

  klass = instances.first.class

  fresh_instances = klass.where(conditions).order(order)
  instances.each do |instance|
    matched_instance = fresh_instances.detect do |fresh_instance|
      keys.all? { |key| fresh_instance.send(key) == instance.send(key) }
    end

    next unless matched_instance

    instance.send :clear_aggregation_cache
    instance.send :clear_association_cache
    instance.instance_variable_set :@attributes, matched_instance.instance_variable_get(:@attributes)

    if instance.respond_to?(:clear_changes_information)
      instance.clear_changes_information                      # Rails 4.2 and higher
    else
      instance.instance_variable_set :@attributes_cache, {}   # Rails 4.0, 4.1
      instance.changed_attributes.clear                       # Rails 3.2
      instance.previous_changes.clear
    end

    # Since the instance now accurately reflects the record in
    # the database, ensure that instance.persisted? is true.
    instance.instance_variable_set '@new_record', false
    instance.instance_variable_set '@destroyed', false
  end
end

Instance Method Details

#synchronize(instances, key = [ActiveRecord::Base.primary_key]) ⇒ Object

See ActiveRecord::ConnectionAdapters::AbstractAdapter.synchronize



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# File 'lib/activerecord-import/synchronize.rb', line 62

def synchronize(instances, key = [ActiveRecord::Base.primary_key])
  self.class.synchronize(instances, key)
end