Question

我无法在IdCell列上创建where子句，但我可以执行“order by”。

SQL服务器说列名称错误

    select 
    *, (ISNULL(Table_Adresses.IdCellule, Table_Clients.IdCellule)) as IdCell
    from Table_Tickets 
    left join Table_Postes on Table_Postes.IdPoste = Table_Tickets.IdPoste
    left join Table_Adresses on Table_Adresses.IdAdresse = Table_Postes.IdAdressePhysique
    left join Table_Clients on Table_Clients.IdClient = Table_Tickets.IdClient
    where idtypeticket=2 and 
    isnull(bcloture,0)=0 and 
    IdCell =4 --problem here
    order by IdCell

为什么我不能在IdCell上找到一个位置？

谢谢

Answer 1

尽管SQL（该语言）强制您按SELECT-FROM-WHERE-ORDER BY的顺序构建查询，但它（有效地）以FROM-WHERE-SELECT-ORDER BY的顺序执行。这就是为什么您可以在AS子句中使用IdCell子句（“列别名”）ORDER BY但不在WHERE子句中使用IdCell不是WHERE在{{1}}子句的范围内，因为它只在以后出现。

Answer 2

您不能以这种方式使用别名列，您需要执行以下操作：

and (ISNULL(Table_Adresses.IdCellule, Table_Clients.IdCellule)) = 4

Answer 3

   select 
    *, (ISNULL(Table_Adresses.IdCellule, Table_Clients.IdCellule)) as IdCell
    from Table_Tickets 
    left join Table_Postes on Table_Postes.IdPoste = Table_Tickets.IdPoste
    left join Table_Adresses on Table_Adresses.IdAdresse = Table_Postes.IdAdressePhysique
    left join Table_Clients on Table_Clients.IdClient = Table_Tickets.IdClient
    where idtypeticket=2 and 
    isnull(bcloture,0)=0 and 
    (ISNULL(Table_Adresses.IdCellule, Table_Clients.IdCellule)) =4 
    order by IdCell

Answer 4

select 
    *, (ISNULL(Table_Adresses.IdCellule, Table_Clients.IdCellule)) as IdCell
    from Table_Tickets 
    left join Table_Postes on Table_Postes.IdPoste = Table_Tickets.IdPoste
    left join Table_Adresses on Table_Adresses.IdAdresse = Table_Postes.IdAdressePhysique
    left join Table_Clients on Table_Clients.IdClient = Table_Tickets.IdClient
    where idtypeticket=2 and 
    bcloture is null and
    (ISNULL(Table_Adresses.IdCellule, Table_Clients.IdCellule)) = 4 
    order by IdCell

列名sql isnull（）子句在哪里

4 个答案: