如何选择非“唯一”行

Question

我有下表，我必须从中获取非唯一行

+------+------+------+
| id   | idA  |infos |
+----- +------+------+
| 0    | 201  | 1899 |
| 1    | 205  | 1955 |
| 2    | 207  | 1955 |
| 3    | 201  | 1959 |
+------+------+------+

我想获取列infos所有行，它们在至少两行中具有相同的idA值。

必须输出上表的查询

infos
1899
1959 

我尝试了以下请求但没有成功：

• SELECT idA FROM XXX WHERE NOT EXISTS(SELECT * FROM XXX GROUP BY idA)
• SELECT * FROM XXX a WHERE NOT EXISTS(SELECT * FROM XXX b WHERE a.RVT_ID=b.RVT_ID GROUP BY idA)

Answer 1

尝试这个：

SELECT T1.idA, T1.infos
FROM XXX T1
JOIN
(
    SELECT idA
    FROM XXX
    GROUP BY idA
    HAVING COUNT(*) >= 2
) T2
ON T1.idA = T2.idA

您发布的数据的结果：

idaA  infos
201   1899
201   1959

Answer 2

这样的事情应该有效：

SELECT idA, COUNT(*) FROM XXX GROUP BY idA HAVING COUNT(*) > 1

Answer 3

SELECT id, idA, COUNT(infos) AS cnt
FROM mytable
GROUP BY infos
HAVING cnt > 1

Answer 4

这可能是你正在寻找的：

SELECT *, COUNT(DISTINCT infos) FROM table GROUP BY idA HAVING COUNT(DISTINCT infos) > 1;

Answer 5

这应该给出“infos”只出现一次的所有行（在MySQL上测试）

SELECT id, idA, count(infos) AS cnt
FROM mytable
GROUP BY infos
HAVING cnt=1

数据

id  ida     infos
1   201     1955
2   202     1978
3   203     1978
4   204     1956
5   0   1980

结果

id  idA     cnt
1   201     1
4   204     1
5   0   1