Question

我从使用嵌套If语句的同事那里继承了一个电子表格，如下所示：

  =IF(AND([@[Pred Type]]="PR_FS",[@[ST Finish]]="A"),
      0,
      IF(AND([@[Pred Type]]="PR_SS", OR([@[ACT_START_DATE]]<>0,[@[ST Start]]="A")),
         0,
         IF(AND([@[Pred Type]]="PR_SF",OR([@[ACT_START_DATE]]<>0,[@[ST Start]]="A")),
            0,
            IF(AND([@[Pred Type]]="PR_FF",[@[STFinish]]="A"),0,1)
           )
        )
     )

我知道我可以编写一个CASE语句来模仿它，但无法弄清楚它的语法。我试过了：

,CASE   WHEN #Preds.Pred_Type = 'PR_FS' and #Tbl_Sched_Act.Expected_Finish = 'A' THEN 0 
    WHEN #Preds.Pred_Type = 'PR_SS' OR ACT_START_DATE IS NOT NULL OR Start_RAW IS NOT NULL THEN 0
    WHEN #Preds.Pred_Type = 'PR_SF'OR ACT_START_DATE IS NOT NULL OR Start_RAW IS NOT NULL THEN 0
    WHEN #Preds.Pred_Type = 'PR_FF' and #Tbl_Sched_Act.Expected_Finish = 'A' THEN 0 
    ELSE 1
    END as PRED_MET

但是，CASE语句不会将任何项目评估为等于1.它们都评估为0，这是不正确的。

有没有人知道如何正确编写我的CASE声明？

Answer 1

您需要将括号()内的CASE WHEN #Preds.Pred_Type = 'PR_FS' and #Tbl_Sched_Act.Expected_Finish = 'A' THEN 0 WHEN #Preds.Pred_Type = 'PR_SS' AND (ACT_START_DATE <> 0 OR Start_RAW <> 0) THEN 0 WHEN #Preds.Pred_Type = 'PR_SF' AND (ACT_START_DATE <> 0 OR Start_RAW <> 0) THEN 0 WHEN #Preds.Pred_Type = 'PR_FF' and #Tbl_Sched_Act.Expected_Finish = 'A' THEN 0 ELSE 1 END as PRED_MET分组以强制运算符优先。

<> 0

注意： ：如果数字为NOT NULL，那么CASE WHEN #Tbl_Sched_Act.Expected_Finish = 'A' AND #Preds.Pred_Type IN ('PR_FS', 'PR_FF') THEN 0 WHEN (ACT_START_DATE <> 0 OR Start_RAW <> 0) AND (#Preds.Pred_Type IN ('PR_SS','PR_SF') THEN 0 ELSE 1 END as PRED_MET DEMO

但这也可以简化为：

select users.name as name,cu.*,ca.*
from users
left join (
    select created_by,
    sum(CASE WHEN amount > 0 THEN amount END) as current_positive,
    sum(CASE WHEN amount < 0 THEN amount END) as current_negative
    from current_transaction
    where created_at between :start_date and :end_date
    group by created_by
) cu on users.id = cu.created_by
left join (
    select created_by,
    sum(CASE WHEN amount > 0 THEN amount END) as cash_positive,
    sum(CASE WHEN amount < 0 THEN amount END) as cash_negative
    from cash_transaction
    where created_at between :start_date and :end_date
    group by created_by
) ca on users.id = ca.created_by
where users.type = 3

嵌套If语句在SQL Server中使用Case语句

1 个答案: