SELECT DISTINCT EventId
FROM table t1
JOIN table t2 USING (EventId)
WHERE t1.TagId = 149
  AND t2.TagId = 150

如果(EventId, TagId)是唯一的，则不需要DISTINCT。

这可以通过以下方式完成：

SELECT EventId
FROM Events_Tags
WHERE TagId IN (149, 150)
GROUP BY EventId
HAVING COUNT(CASE WHEN TagId = 149 then 1 end) = 1  AND COUNT(CASE WHEN TagId = 149 then 1 end) = 1;

或者简单地说：

SELECT EventId
FROM Events_Tags
WHERE TagId IN (149, 150)
GROUP BY EventId
HAVING COUNT(DISTINCT TagId) = 2;

Demo here

这适用于查找至少具有以下两个标记的事件：

SELECT EventId
FROM Events_Tags
WHERE TagId IN (149, 150)
GROUP BY EventId
HAVING COUNT(DISTINCT TagId) = 2;