MySQL查询不区分,计数
我试着用一个精选的表格来找出有多少人有车,有多少人有船,现在有多少自行车等等MySQL查询不区分,计数,mysql,count,distinct,Mysql,Count,Distinct,我试着用一个精选的表格来找出有多少人有车,有多少人有船,现在有多少自行车等等 | name | obj | --------------------- | john | car | | mary | boat | | dave | car | | james | bike | | steve | car | | walt | bike | 例如:bike-2您可以使用此查询 select sum(obj =
| name | obj |
---------------------
| john | car |
| mary | boat |
| dave | car |
| james | bike |
| steve | car |
| walt | bike |
例如:bike-2您可以使用此查询
select sum(obj = 'car') as car_count,
sum(obj = 'boat') as boat_count
from your_table
SELECT obj, COUNT(name) as nb FROM table GROUP BY obj ORDER BY obj
结果():
select distinct
按行工作。它不过滤不同的字段内容。您需要一个选择obj,计数(obj)。。。改为按obj分组。可以工作,但如果我有100种类型的对象呢?在我的例子中,我有23个不同的对象。谢谢你的回答!
| obj | nb |
---------------------
| bike | 2 |
| boat | 1 |
| car | 3 |