Class: Arel::Nodes::Extract

Inherits:
Unary show all
Includes:
Expression, Predications
Defined in:
lib/arel/nodes/extract.rb

Instance Attribute Summary collapse

Attributes inherited from Unary

#expr

Instance Method Summary collapse

Methods included from Predications

#does_not_match, #does_not_match_all, #does_not_match_any, #eq, #eq_all, #eq_any, #gt, #gt_all, #gt_any, #gteq, #gteq_all, #gteq_any, #in, #in_all, #in_any, #lt, #lt_all, #lt_any, #lteq, #lteq_all, #lteq_any, #matches, #matches_all, #matches_any, #not_eq, #not_eq_all, #not_eq_any, #not_in, #not_in_all, #not_in_any

Methods included from OrderPredications

#asc, #desc

Methods inherited from Node

#_caller, #and, #each, #not, #or, #to_sql

Methods included from FactoryMethods

#create_and, #create_false, #create_join, #create_on, #create_string_join, #create_table_alias, #create_true, #grouping, #lower

Constructor Details

#initialize(expr, field, aliaz = nil) ⇒ Extract

Returns a new instance of Extract.


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# File 'lib/arel/nodes/extract.rb', line 11

def initialize expr, field, aliaz = nil
  super(expr)
  @field = field
  @alias = aliaz && SqlLiteral.new(aliaz)
end

Instance Attribute Details

#aliasObject

Returns the value of attribute alias


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# File 'lib/arel/nodes/extract.rb', line 9

def alias
  @alias
end

#fieldObject

Returns the value of attribute field


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# File 'lib/arel/nodes/extract.rb', line 8

def field
  @field
end

Instance Method Details

#as(aliaz) ⇒ Object


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# File 'lib/arel/nodes/extract.rb', line 17

def as aliaz
  self.alias = SqlLiteral.new(aliaz)
  self
end

#eql?(other) ⇒ Boolean Also known as: ==

Returns:

  • (Boolean)

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# File 'lib/arel/nodes/extract.rb', line 26

def eql? other
  super &&
    self.field == other.field &&
    self.alias == other.alias
end

#hashObject


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# File 'lib/arel/nodes/extract.rb', line 22

def hash
  super ^ [@field, @alias].hash
end