如何根据列中值的计数比较来提取记录

Question

请原谅标题,但我不知道写什么.所以这就是我所拥有的 -

CUSTOMER(KEY, IDENT, DEBIT_CREDIT)

1,1000,'D'
2,1000,'C'
3,1001,'D'
4,1000,'D'
5,1000,'D'
.
.
.

我想编写一个SQL Server查询,以便IDENT在"D"计数大于"C"计数的情况下进行相同的查询

Answer 1

第一:

SELECT IDENT
FROM CUSTOMER
GROUP BY IDENT
HAVING  SUM(CASE WHEN DEBIT_CREDIT = 'D' THEN 1 ELSE 0 END) >
        SUM(CASE WHEN DEBIT_CREDIT = 'C' THEN 1 ELSE 0 END)

第二:

SELECT IDENT
FROM CUSTOMER
GROUP BY IDENT
HAVING  SUM(CASE WHEN DEBIT_CREDIT = 'D' THEN 1 ELSE 0 END) =
        SUM(CASE WHEN DEBIT_CREDIT = 'C' THEN 1 ELSE 0 END)