返回空值IN子句mysql

您需要使用其他方法。您将需要使用UNIOn ALL创建具有所有值的内联视图，然后将其与users表保持连接：

SQL小提琴

查询1 ：

SELECt a.uid, (CASE WHEN (u.uid is null) THEN 'not found' ELSE 'found' END) as     resultFROM (select 1 as UID FROM dual      UNIOn ALL      select 2 as UID FROM dual      UNIOn ALL      select 56443 as UID FROM dual      UNIOn ALL      select 3 as UID FROM dual) as aLEFT JOIN users u on a.uid = u.uid

[结果] ：

|   UID |    result ||-------|-----------||     1 |     found ||     2 |     found ||     3 |     found || 56443 | not found |