SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 1) ExpressionList (children 2) Function leftPad (children 1) ExpressionList (children 2) Function toFixedString (children 1) ExpressionList (children 2) Literal \'abc\' Literal UInt64_3 Literal UInt64_0 Function leftPad (children 1) ExpressionList (children 2) Literal \'abc\' Function CAST (children 1) ExpressionList (children 2) Literal \'0\' Literal \'Int32\'