mysql 查询数据为空如何设置默认值

Question

如何把查询出来的null 默认为0;

SQL是:select name,sum(score) as cou from student left join score on (student.id=score.stu_id) group by stu_id order by cou desc;

求指导

Answer 1

select name,sum(if(score is null,0,score)) as cou from student left join score on (student.id=score.stu_id) group by stu_id order by cou desc;

试一下这个