SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 2)
    Function toUInt64 (alias x) (children 1)
     ExpressionList (children 1)
      Literal UInt64_9223372036854775808
    Function equals (children 1)
     ExpressionList (children 2)
      Identifier b
      Identifier x
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier decimal
   Function equals (children 1)
    ExpressionList (children 2)
     Identifier a
     Literal UInt64_42
