AlterQuery  t0 (children 3)
 ExpressionList (children 1)
  AlterCommand UPDATE (children 2)
   Function exists (children 1)
    ExpressionList (children 1)
     Subquery (children 1)
      SelectWithUnionQuery (children 1)
       ExpressionList (children 1)
        SelectQuery (children 1)
         ExpressionList (children 1)
          Literal UInt64_1
   ExpressionList (children 2)
    Assignment c0 (children 1)
     Function tuple (children 1)
      ExpressionList
    Assignment c1 (children 1)
     Literal UInt64_2
 Identifier t0
 Set
