摘要： 主要是GROUPING SETS和ROLLUP函数，具体意思不好说清楚，只能通过例子来学习。原表数据，如下图GROUPING SETS测试，下面两段代码运行结果是一样，select id,area,stu_type,sum(score) score from studentsgroup by grouping sets(id,area,stu_type)select a.id, null, null, sum( score ) from students a group by a.idunion allselect null, a.area, null, sum( score ) from s 阅读全文