Question

我想查找排名，然后根据其ID更新其排名列。

我的数据如下（表成员）。

MEMBER_ID | LOAN_AMOUNT | Rank 
1         | 2,000.00    |  0
2         | 1,000.00    |  0
3         | 4,000.00    |  0
4         | 1,000.00    |  0

现在我想找到他们的排名并根据它更新排名列。我的一般查询是这样的：

UPDATE
Member AS dest,
(
    SELECT RANK() OVER(ORDER BY t.loan_amount DESC) as [rank],
     t.memeber_id,t.loan_amount
FROM Member
) AS src
SET
dest.rank = src.rank
INNER JOIN dest.memeber_id = src.memeber_id

有没有更快的方法来更新我的桌子？

Answer 1

在mysql中，更新连接的sintax应该为

UPDATE
Member AS dest
INNER JOIN 
(
    SELECT RANK() OVER(ORDER BY t.loan_amount DESC) as [rank],
     t.memeber_id,t.loan_amount
FROM Member
) src ON dest.memeber_id = src.memeber_id
SET dest.rank = src.rank

无论如何，您都应该避免在计算过程中轻松计算存储的数据..在执行选择的同时，也可以轻松获取rank（）

选择内部联接并在单个查询中更新

1 个答案: