Module: ActiveRecord::QueryMethods

Extended by:
ActiveSupport::Concern
Included in:
Relation
Defined in:
activerecord/lib/active_record/relation/query_methods.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from ActiveSupport::Concern

append_features, extended, included

Instance Attribute Details

#bind_valuesObject

Returns the value of attribute bind_values


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def bind_values
  @bind_values
end

#create_with_valueObject

Returns the value of attribute create_with_value


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def create_with_value
  @create_with_value
end

#eager_load_valuesObject

Returns the value of attribute eager_load_values


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def eager_load_values
  @eager_load_values
end

#from_valueObject

Returns the value of attribute from_value


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def from_value
  @from_value
end

#group_valuesObject

Returns the value of attribute group_values


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def group_values
  @group_values
end

#having_valuesObject

Returns the value of attribute having_values


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def having_values
  @having_values
end

#includes_valuesObject

Returns the value of attribute includes_values


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def includes_values
  @includes_values
end

#joins_valuesObject

Returns the value of attribute joins_values


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def joins_values
  @joins_values
end

#limit_valueObject

Returns the value of attribute limit_value


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def limit_value
  @limit_value
end

#lock_valueObject

Returns the value of attribute lock_value


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def lock_value
  @lock_value
end

#offset_valueObject

Returns the value of attribute offset_value


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def offset_value
  @offset_value
end

#order_valuesObject

Returns the value of attribute order_values


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def order_values
  @order_values
end

#preload_valuesObject

Returns the value of attribute preload_values


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def preload_values
  @preload_values
end

#readonly_valueObject

Returns the value of attribute readonly_value


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def readonly_value
  @readonly_value
end

#reordering_valueObject

Returns the value of attribute reordering_value


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def reordering_value
  @reordering_value
end

#reverse_order_valueObject

Returns the value of attribute reverse_order_value


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def reverse_order_value
  @reverse_order_value
end

#select_valuesObject

Returns the value of attribute select_values


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def select_values
  @select_values
end

#uniq_valueObject

Returns the value of attribute uniq_value


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def uniq_value
  @uniq_value
end

#where_valuesObject

Returns the value of attribute where_values


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 8

def where_values
  @where_values
end

Instance Method Details

#arelObject


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 259

def arel
  @arel ||= with_default_scope.build_arel
end

#bind(value) ⇒ Object


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 126

def bind(value)
  relation = clone
  relation.bind_values += [value]
  relation
end

#build_arelObject


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 263

def build_arel
  arel = table.from table

  build_joins(arel, @joins_values) unless @joins_values.empty?

  collapse_wheres(arel, (@where_values - ['']).uniq)

  arel.having(*@having_values.uniq.reject{|h| h.blank?}) unless @having_values.empty?

  arel.take(connection.sanitize_limit(@limit_value)) if @limit_value
  arel.skip(@offset_value.to_i) if @offset_value

  arel.group(*@group_values.uniq.reject{|g| g.blank?}) unless @group_values.empty?

  order = @order_values
  order = reverse_sql_order(order) if @reverse_order_value
  arel.order(*order.uniq.reject{|o| o.blank?}) unless order.empty?

  build_select(arel, @select_values.uniq)

  arel.distinct(@uniq_value)
  arel.from(@from_value) if @from_value
  arel.lock(@lock_value) if @lock_value

  arel
end

#create_with(value) ⇒ Object


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 179

def create_with(value)
  relation = clone
  relation.create_with_value = value ? create_with_value.merge(value) : {}
  relation
end

#eager_load(*args) ⇒ Object


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 25

def eager_load(*args)
  return self if args.blank?

  relation = clone
  relation.eager_load_values += args
  relation
end

#extending(*modules) ⇒ Object

Used to extend a scope with additional methods, either through a module or through a block provided.

The object returned is a relation, which can be further extended.

Using a module

module Pagination
  def page(number)
    # pagination code goes here
  end
end

scope = Model.scoped.extending(Pagination)
scope.page(params[:page])

You can also pass a list of modules:

scope = Model.scoped.extending(Pagination, SomethingElse)

Using a block

scope = Model.scoped.extending do
  def page(number)
    # pagination code goes here
  end
end
scope.page(params[:page])

You can also use a block and a module list:

scope = Model.scoped.extending(Pagination) do
  def per_page(number)
    # pagination code goes here
  end
end

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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 243

def extending(*modules)
  modules << Module.new(&Proc.new) if block_given?

  return self if modules.empty?

  relation = clone
  relation.send(:apply_modules, modules.flatten)
  relation
end

#from(value) ⇒ Object


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 185

def from(value)
  relation = clone
  relation.from_value = value
  relation
end

#group(*args) ⇒ Object


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 80

def group(*args)
  return self if args.blank?

  relation = clone
  relation.group_values += args.flatten
  relation
end

#having(opts, *rest) ⇒ Object


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 140

def having(opts, *rest)
  return self if opts.blank?

  relation = clone
  relation.having_values += build_where(opts, rest)
  relation
end

#includes(*args) ⇒ Object


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 15

def includes(*args)
  args.reject! {|a| a.blank? }

  return self if args.empty?

  relation = clone
  relation.includes_values = (relation.includes_values + args).flatten.uniq
  relation
end

#joins(*args) ⇒ Object


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 115

def joins(*args)
  return self if args.compact.blank?

  relation = clone

  args.flatten!
  relation.joins_values += args

  relation
end

#limit(value) ⇒ Object


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 148

def limit(value)
  relation = clone
  relation.limit_value = value
  relation
end

#lock(locks = true) ⇒ Object


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 160

def lock(locks = true)
  relation = clone

  case locks
  when String, TrueClass, NilClass
    relation.lock_value = locks || true
  else
    relation.lock_value = false
  end

  relation
end

#offset(value) ⇒ Object


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 154

def offset(value)
  relation = clone
  relation.offset_value = value
  relation
end

#order(*args) ⇒ Object


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 88

def order(*args)
  return self if args.blank?

  relation = clone
  relation.order_values += args.flatten
  relation
end

#preload(*args) ⇒ Object


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 33

def preload(*args)
  return self if args.blank?

  relation = clone
  relation.preload_values += args
  relation
end

#readonly(value = true) ⇒ Object


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 173

def readonly(value = true)
  relation = clone
  relation.readonly_value = value
  relation
end

#reorder(*args) ⇒ Object

Replaces any existing order defined on the relation with the specified order.

User.order('email DESC').reorder('id ASC') # generated SQL has 'ORDER BY id ASC'

Subsequent calls to order on the same relation will be appended. For example:

User.order('email DESC').reorder('id ASC').order('name ASC')

generates a query with 'ORDER BY id ASC, name ASC'.


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 106

def reorder(*args)
  return self if args.blank?

  relation = clone
  relation.reordering_value = true
  relation.order_values = args.flatten
  relation
end

#reverse_orderObject


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 253

def reverse_order
  relation = clone
  relation.reverse_order_value = !relation.reverse_order_value
  relation
end

#select(value = Proc.new) ⇒ Object

Works in two unique ways.

First: takes a block so it can be used just like Array#select.

Model.scoped.select { |m| m.field == value }

This will build an array of objects from the database for the scope, converting them into an array and iterating through them using Array#select.

Second: Modifies the SELECT statement for the query so that only certain fields are retrieved:

>> Model.select(:field)
=> [#<Model field:value>]

Although in the above example it looks as though this method returns an array, it actually returns a relation object and can have other query methods appended to it, such as the other methods in ActiveRecord::QueryMethods.

The argument to the method can also be an array of fields.

>> Model.select([:field, :other_field, :and_one_more])
=> [#<Model field: "value", other_field: "value", and_one_more: "value">]

Any attributes that do not have fields retrieved by a select will raise a ActiveModel::MissingAttributeError when the getter method for that attribute is used:

>> Model.select(:field).first.other_field
=> ActiveModel::MissingAttributeError: missing attribute: other_field

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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 70

def select(value = Proc.new)
  if block_given?
    to_a.select {|*block_args| value.call(*block_args) }
  else
    relation = clone
    relation.select_values += Array.wrap(value)
    relation
  end
end

#uniq(value = true) ⇒ Object

Specifies whether the records should be unique or not. For example:

User.select(:name)
# => Might return two records with the same name

User.select(:name).uniq
# => Returns 1 record per unique name

User.select(:name).uniq.uniq(false)
# => You can also remove the uniqueness

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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 201

def uniq(value = true)
  relation = clone
  relation.uniq_value = value
  relation
end

#where(opts, *rest) ⇒ Object


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# File 'activerecord/lib/active_record/relation/query_methods.rb', line 132

def where(opts, *rest)
  return self if opts.blank?

  relation = clone
  relation.where_values += build_where(opts, rest)
  relation
end