Class: Arel::Nodes::Exists

Inherits:
Unary
  • Object
show all
Includes:
OrderPredications, Predications, WindowPredications
Defined in:
lib/arel/extensions/exists.rb

Overview

www.postgresql.org/docs/10/functions-subquery.html

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(expr, aliaz = nil) ⇒ Exists

Returns a new instance of Exists.



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# File 'lib/arel/extensions/exists.rb', line 23

def initialize(expr, aliaz = nil)
  @expressions = expr
  @alias       = aliaz && SqlLiteral.new(aliaz)
  @distinct    = false
end

Instance Attribute Details

#alias ⇒ Object

Returns the value of attribute alias.



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# File 'lib/arel/extensions/exists.rb', line 21

def alias
  @alias
end

#distinct ⇒ Object

Returns the value of attribute distinct.



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# File 'lib/arel/extensions/exists.rb', line 21

def distinct
  @distinct
end

#expressions ⇒ Object

Returns the value of attribute expressions.



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# File 'lib/arel/extensions/exists.rb', line 21

def expressions
  @expressions
end

Instance Method Details

#as(aliaz) ⇒ Object 



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# File 'lib/arel/extensions/exists.rb', line 29

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/extensions/exists.rb', line 38

def eql?(other)
  self.class == other.class &&
    expressions == other.expressions &&
    self.alias == other.alias &&
    distinct == other.distinct
end

#hash ⇒ Object 



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# File 'lib/arel/extensions/exists.rb', line 34

def hash
  [@expressions, @alias, @distinct].hash
end