小编Seb*_*cia的帖子

在我的情况下,我有2个项目项目和活动,他们看起来像这样.

项目是顶部的表格和底部的活动.

在Activity表中,activityID和projectID是主键.

我想要实现的是创建一个View,它返回所有项目,其活动的endDate晚于Project projectionEndDate.

总之,我想这样做:

SELECT *
FROM Project
WHERE (SELECT MAX(endDate) FROM Activity GROUP BY projectID) > projectedEndDate

但是我收到以下错误:

Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.

谢谢