Question

如何查询“SQL计算表中一个列中各数的出现次数”？

Answer 1

select countB)from A group by B order by B

SQL语句就可以做了,例检索表格aaa,添加一列“re_num”,显示a列值重复的次数，

次数为表格按a列分组计算记录数：

select a,count(a) as 're_num' from aaa group by a，

select a1.a2.re_num from 

aaa a1 

join 

(select a,count(a) as 're_num' from aaa group by a) a2 

on a1.a = a2.a;

select sum(datac.COUNT_VALUE)

from T_JL_COUNT_DATA datac

, T_JL_XC_RESULT a

where datac.COUNT_NO=45 and a.id=datac.RESULT_ID。