求一条汇总的sql语句,谢谢

Question

数据如下
no、school(学校),  grade(学期), stuName(学生), shouldPay(应交学费)
1     龙山               第1学期              zs1                2000                     
2     龙山               第1学期              zs2                2000
3     龙山               第1学期              zs3                2000
4     龙山               第1学期              zs4                20005     龙山               第2学期              zs5                3000
6     龙山               第2学期              zs6                3000
7     龙山               第2学期              zs7                3000
8     龙山               第2学期              zs8                3000
9     龙山               第2学期              zs9                3000用一条sql语句统计出应交费的总额
就是第1学期  2000*4(人) + 3000*5(人)
结果为   23000
谢谢大家

Answer 1

可能你的想法没表达清楚吧   组织下语言先如果要结果  直接select sum(shouldPay) from 表

Answer 2

select school, grade, sum(shouldPay) from 表名 group by school, grade
可以根据学校，表名分组统计学费

Answer 3

select school, grade, sum(shouldPay) from 表名 group by school, grade