SELECT 'id' FROM `table` WHERE `id` =
(select min(`id`) FROM `table` where
`id` < 1 and `ids` = 1)
id ids
1 1
2 1
5 1
6 1
结果:
id = ''
我需要将id=''
更改为id='n/a'
答案 0 :(得分:1)
如果查询返回null结果,则可以使用COALESCE:
SELECT COALESCE('id','N/A') FROM ...
如果返回结果为空字符串,则可以执行以下操作:
SELECT CASE WHEN id = '' THEN 'N/A' ELSE id END FROM ...
答案 1 :(得分:0)
另一种选择是:IFNULL