用一条语句实现例如:更新文章的 作者字段。
如果作者为空字符串,则写上 yuna123.
如果作者不为空字符串,则在原作者名字上打上括号: 例如 (xiaoming)
update article set author = (这里判断写?)
如果作者为空字符串,则写上 yuna123.
如果作者不为空字符串,则在原作者名字上打上括号: 例如 (xiaoming)
update article set author = (这里判断写?)
update article set author = case when author is null then 'yuna123' else '('+author+')' end
(
ID INT IDENTITY,
NAME VARCHAR(20)
)
INSERT INTO #TP SELECT 'Evan'
INSERT INTO #TP SELECT ''
INSERT INTO #TP SELECT 'Shadow'
INSERT INTO #TP SELECT 'Tim'
INSERT INTO #TP SELECT ''SELECT * FROM #TP tUPDATE #TP
SET NAME=(CASE WHEN NAME='' THEN 'yuna123' ELSE '(' +NAME +')' END)ID NAME
----------- --------------------
1 (Evan)
2 yuna123
3 (Shadow)
4 (Tim)
5 yuna123(5 row(s) affected)