SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 3)
    Identifier _database
    Identifier _table
    Identifier n
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Function merge (children 1)
       ExpressionList
   ExpressionList (children 3)
    OrderByElement (children 1)
     Identifier _database
    OrderByElement (children 1)
     Identifier _table
    OrderByElement (children 1)
     Identifier n
