SELECT DISTINCT docid FROM docimagefile WHERE docid IN ( SELECT docid FROM docimagefile GROUP BY docid HAVING COUNT(1) > 1 AND MIN(docfiletype) <> MAX(docfiletype) ); 只查 里面isextfile 为空的怎么写
时间: 2024-01-13 20:03:10 浏览: 23
如果您只想查询 `isextfile` 为空的记录,可以在 `WHERE` 子句中加入条件 `isextfile IS NULL`,如下所示:
```
SELECT DISTINCT docid
FROM docimagefile
WHERE docid IN (
SELECT docid
FROM docimagefile
GROUP BY docid
HAVING COUNT(1) > 1 AND MIN(docfiletype) <> MAX(docfiletype)
) AND isextfile IS NULL;
```
这将仅返回 `isextfile` 为空的记录所对应的 `docid`。