更新與其他列具有一個或多個相同值的列值

Question

我有這樣的聲明：

UPDATE `tblAllocatedLeads` 
SET tblAllocatedLeads.fldAllocatedStatus = CASE 
WHEN tblAllocatedLeads.fldAllocatedStatus = 'Allocated' 
AND 
(SELECT COUNT(*) FROM (SELECT * FROM `tblAllocatedLeads`) AS tblallocate WHERE AND tblallocate.fldAllocatedLeadId = tblAllocatedLeads.fldAllocatedLeadId) > 1 
THEN 'Outstanding' 
END

我想要的是將fldAllocatedStatus = 'Allocated' 的所有行更新為 'Outstanding' ，這些行具有一個或多個相同的列fldAllocatedLeadId值到其他行。

我的數據

ID   fldAllocatedStatus   fldAllocatedLeadId
1    Accepted             123
2    Rejected             123
3    Allocated            123
4    Allocated            321

在這種情況下， ID = 3應將fldAllocatedStatus更新為“Outstanding”，因為它具有一個或多個來自ID = 1,2 的相同fldAllocatedLeadId

並且ID = 4應該保持“已分配”，因為它沒有fldAllocatedLeadId與其他行的匹配。

現在它所做的甚至更新了“接受，拒絕” ，它應該只更新帶有“已分配”的行

Answer 1

您不需要任何聚合，只需一個自連接：

UPDATE tblAllocatedLeads t 
INNER JOIN tblAllocatedLeads tt
ON tt.id <> t.id AND tt.fldAllocatedLeadId = t.fldAllocatedLeadId 
SET t.fldAllocatedStatus = 'Outstanding' 
WHERE t.fldAllocatedStatus = 'Allocated';

請參閱演示。
結果：

| ID  | fldAllocatedStatus | fldAllocatedLeadId |
| --- | ------------------ | ------------------ |
| 1   | Accepted           | 123                |
| 2   | Rejected           | 123                |
| 3   | Outstanding        | 123                |
| 4   | Allocated          | 321                |

Answer 2

假設 MySQL，我認為你想要：

UPDATE tblAllocatedLeads al JOIN
       (SELECT al2.fldAllocatedLeadId
        FROM tblAllocatedLeads al2
        WHERE al.fldAllocatedStatus <> 'Allocated'
        GROUP BY al2.tblAllocatedLeads
       ) al2
       ON al2.tblAllocatedLeads = al.tblAllocatedLeads
    SET al.fldAllocatedStatus = 'Outstanding'
    WHERE al.fldAllocatedStatus = 'Allocated' ;

子查詢獲取具有某些未分配值的潛在客戶。 外部WHERE只更新分配的行（如果有）。