sql按字段值进行统计
用group by
如有个student表里有性别sex来统计
select sex,count(*) from student group by sex;
转载自:https://blog.csdn.net/markchiu/article/details/51218742
用group by
如有个student表里有性别sex来统计
select sex,count(*) from student group by sex;
转载自:https://blog.csdn.net/markchiu/article/details/51218742