SelectWithUnionQuery (children 2)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 2)
    Function length (children 1)
     ExpressionList (children 1)
      Identifier arr
    Function isNull (children 1)
     ExpressionList (children 1)
      Identifier n
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier t_column_names
 Identifier JSONEachRow
