更新声明以增加列值

Posted 2021-03-19

请考虑以下设置

Control Group   Sequence
Cont1   Group1  0
Cont2   Group1  1
Cont3   Group1  2
Cont3   Group2  0
Cont2   Group2  1
Cont1   Group2  2

对于序列>=cont2的序列和各组的序列，用+1进行递增。

结果应该是

Control Group   Sequence
Cont1   Group1  0
Cont2   Group1  2
Cont3   Group1  3
Cont3   Group2  0
Cont2   Group2  2
Cont1   Group2  3

有谁能帮我构造Sql来得到上述结果？

答案

我想这就是你想要的。

update setup
    set sequence = sequence + 1
    where sequence >= (select s2.sequence
                       from setup s2
                       where s2.group = s.group and s2.control = 'Cont2'
                      );

另一答案

你也可以用OUTER APPLY试试另一种解决方案。

UPDATE s
    SET s.[Sequence] = s.[Sequence]+1
FROM setup s
OUTER APPLY
(
    SELECT s2.[Sequence]
    FROM setup s2
    WHERE s2.[Group] = s.[Group] AND s2.[Control] = 'Cont2'
)_
WHERE s.[Sequence] >= _.[Sequence]