Question

我目前有一个表，可以说它有约100行数据。其中一列“ UserName”目前在88行中为空。包含数据的12行如下所示：

User1
User2
User3
User4
User5
User6
etc

我想用User13，User14等填充88行中的其余行。如何更新这些行以使用递增的值？

Answer 1

我建议您更新CTE。这有点棘手，因为您需要继续编号，但是我认为这可行：

with toupdate as (
      select t.*,
             row_number() over (order by (select null)) as seqnum,
             max(convert(int, stuff(username, 1, 4, ''))) over () as maxnum
      from t
     )
update toupdate
    set username = 'User' + convert(varchar(255), seqnum + maxnum)
    where username is null;

如果不提醒您更新所有行，则可以使用：

with toupdate as (
      select t.*,
             row_number() over (order by case when username is not null then convert(int, stuff(username, 1, 4, '')) else 999999 end) as seqnum
      from t
     )
update toupdate
    set username = 'User' + convert(varchar(255), seqnum);

这应该保持现有的顺序，但是如果有差距，那就可以消除它们。

Answer 2

会进行以下工作吗？

;WITH UserTable
AS
(
    SELECT ROW_NUMBER() OVER(ORDER BY [user] DESC) as [row], 
           [UserName] as [user]
    FROM MyUserTable
) 
UPDATE u
SET 'User' + CAST(row AS varchar(10)) 
FROM UserTable u
WHERE u.[user] IS NULL

用增量值更新列

2 个答案: