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求个mysql话语
- WBOYOriginal
- 2016-06-13 13:07:42863browse
求个mysql语句
id parent_id num
1 0 1
2 1 5
3 1 4
4 0 2
5 4 3
我想要查询parent_id=0,并且parent_id对应id的sum(num)的值;
既是parent_id=0的id=1，我需要得到的num的值是1+5+4
能不能用mysql语句实现？
------解决方案--------------------
我想要查询parent_id=0,并且parent_id对应id的sum(num)的值:
select count(num) as sum from 表 where parent_id =0
下面这句什么意思？
既是parent_id=0的id=1，我需要得到的num的值是1+5+4
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