mysql count 怎么提交效率

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有一个程序,先从user表查一定数量的用户$data，再foreach数组，从user表里count(*) where pid=$value['id'] 来统计子集数量

循环200条数据需要5秒多，要是数据多估计就卡死了，该怎么优化？

8 years, 11 months ago

Falken 8 years, 11 months ago

用Count(1)而不是count(*)可以有一定改善

answered 8 years, 11 months ago

就烦起名字 answered 8 years, 11 months ago

连接查询count(*)使用group by

answered 8 years, 11 months ago

阿酱的小池 answered 8 years, 11 months ago