SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 2)
    Identifier t.a
    Identifier u.a
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias t) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Literal UInt64_1 (alias a)
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      Subquery (alias u) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 2)
          ExpressionList (children 1)
           Literal UInt64_1 (alias a)
          Function equals (children 1)
           ExpressionList (children 2)
            Literal UInt64_0
            Identifier t.a (alias alias668)
     TableJoin
