Class: ActiveRecord::Relation::WhereClause

Inherits:
Object
  • Object
show all
Defined in:
activerecord/lib/active_record/relation/where_clause.rb

Overview

:nodoc:

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(predicates) ⇒ WhereClause

Returns a new instance of WhereClause.


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

def initialize(predicates)
  @predicates = predicates
end

Class Method Details

.emptyObject


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# File 'activerecord/lib/active_record/relation/where_clause.rb', line 85

def self.empty
  @empty ||= new([]).tap(&:referenced_columns).freeze
end

Instance Method Details

#+(other) ⇒ Object


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# File 'activerecord/lib/active_record/relation/where_clause.rb', line 12

def +(other)
  WhereClause.new(
    predicates + other.predicates,
  )
end

#-(other) ⇒ Object


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# File 'activerecord/lib/active_record/relation/where_clause.rb', line 18

def -(other)
  WhereClause.new(
    predicates - other.predicates,
  )
end

#==(other) ⇒ Object


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# File 'activerecord/lib/active_record/relation/where_clause.rb', line 68

def ==(other)
  other.is_a?(WhereClause) &&
    predicates == other.predicates
end

#astObject


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# File 'activerecord/lib/active_record/relation/where_clause.rb', line 64

def ast
  Arel::Nodes::And.new(predicates_with_wrapped_sql_literals)
end

#contradiction?Boolean

Returns:

  • (Boolean)

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# File 'activerecord/lib/active_record/relation/where_clause.rb', line 89

def contradiction?
  predicates.any? do |x|
    case x
    when Arel::Nodes::In
      Array === x.right && x.right.empty?
    when Arel::Nodes::Equality
      x.right.respond_to?(:unboundable?) && x.right.unboundable?
    end
  end
end

#except(*columns) ⇒ Object


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# File 'activerecord/lib/active_record/relation/where_clause.rb', line 30

def except(*columns)
  WhereClause.new(except_predicates(columns))
end

#invert(as = :nand) ⇒ Object


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# File 'activerecord/lib/active_record/relation/where_clause.rb', line 73

def invert(as = :nand)
  if predicates.size == 1
    inverted_predicates = [ invert_predicate(predicates.first) ]
  elsif as == :nor
    inverted_predicates = predicates.map { |node| invert_predicate(node) }
  else
    inverted_predicates = [ Arel::Nodes::Not.new(ast) ]
  end

  WhereClause.new(inverted_predicates)
end

#merge(other) ⇒ Object


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# File 'activerecord/lib/active_record/relation/where_clause.rb', line 24

def merge(other)
  WhereClause.new(
    predicates_unreferenced_by(other) + other.predicates,
  )
end

#or(other) ⇒ Object


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# File 'activerecord/lib/active_record/relation/where_clause.rb', line 34

def or(other)
  left = self - other
  common = self - left
  right = other - common

  if left.empty? || right.empty?
    common
  else
    or_clause = WhereClause.new(
      [left.ast.or(right.ast)],
    )
    common + or_clause
  end
end

#to_h(table_name = nil) ⇒ Object


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# File 'activerecord/lib/active_record/relation/where_clause.rb', line 49

def to_h(table_name = nil)
  equalities = equalities(predicates)
  if table_name
    equalities = equalities.select do |node|
      node.left.relation.name == table_name
    end
  end

  equalities.map { |node|
    name = node.left.name.to_s
    value = extract_node_value(node.right)
    [name, value]
  }.to_h
end