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