Question

请参阅此SQL小提琴：http://sqlfiddle.com/#!3/068e9/3/0
（MS Sql Server 2008）

架构的设置是：

create table test_replace ( something varchar(50));

insert into test_replace(something) values('072 782 5343');
insert into test_replace(something) values('071 647 2342');
insert into test_replace(something) values('whatever@something.com');

查询是：

select case when CHARINDEX('@', something,0) > -1
then REPLACE(something,'@','@testtesttest')
else REPLACE(something,' ','') end as test1,
REPLACE(something,' ','') as test2
from test_replace

CASE语句中的第二个REPLACE不起作用（比较应用于电话号码时test1到test2的输出）。那是为什么？

Answer 1

CHARINDEX在找不到字符串时返回0（不是你的-1）

您的查询应该是：

select case when CHARINDEX('@', something,0) > 0
then REPLACE(something,'@','@testtesttest')
else REPLACE(something,' ','') end as test1,
REPLACE(something,' ','') as test2
from test_replace

Answer 2

CHARINDEX（'@'，'072 782 5343'，0）不是-1而是0

所以在条件

中将-1更改为0

select case when CHARINDEX('@', something,0) > 0
then REPLACE(something,'@','@testtesttest')
else REPLACE(something,' ','') end as test1,
REPLACE(something,' ','') as test2
from test_replace

T-SQL - 为什么REPLACE在Case中无法正常工作？

2 个答案: