module Arel module Visitors class MySQL < Arel::Visitors::ToSql private def visit_Arel_Nodes_Union o, suppress_parens = false left_result = case o.left when Arel::Nodes::Union visit_Arel_Nodes_Union o.left, true else visit o.left end right_result = case o.right when Arel::Nodes::Union visit_Arel_Nodes_Union o.right, true else visit o.right end if suppress_parens "#{left_result} UNION #{right_result}" else "( #{left_result} UNION #{right_result} )" end end def visit_Arel_Nodes_Bin o "BINARY #{visit o.expr}" end ### # :'( # http://dev.mysql.com/doc/refman/5.0/en/select.html#id3482214 def visit_Arel_Nodes_SelectStatement o o.limit = Arel::Nodes::Limit.new(18446744073709551615) if o.offset && !o.limit super end def visit_Arel_Nodes_SelectCore o o.froms ||= Arel.sql('DUAL') super end def visit_Arel_Nodes_UpdateStatement o [ "UPDATE #{visit o.relation}", ("SET #{o.values.map { |value| visit value }.join ', '}" unless o.values.empty?), ("WHERE #{o.wheres.map { |x| visit x }.join ' AND '}" unless o.wheres.empty?), ("ORDER BY #{o.orders.map { |x| visit x }.join(', ')}" unless o.orders.empty?), (visit(o.limit) if o.limit), ].compact.join ' ' end end end end