SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 3) ExpressionList (children 3) Identifier b Identifier a Identifier c TablesInSelectQuery (children 1) TablesInSelectQueryElement (children 1) TableExpression (children 1) TableIdentifier buffer_00126 ExpressionList (children 3) OrderByElement (children 1) Identifier a OrderByElement (children 1) Identifier b OrderByElement (children 1) Identifier c