请问这个语句错在哪里呢?
SELECT E.CourseID, E.Grade, S.FName, S.LName, C.CourseName, C.Instructor, A.AssignmentID FROM ((DB.STUDENT AS S INNER JOIN DB.ENROLLED AS E ON S.StudentID=E.StudentID) INNER JOIN DB.COURSE AS C ON E.CourseID=C.CourseID) INNER JOIN DB.ASSIGNMENT AS A ON E.CourseID=A.CourseID
错误显示:无效的列索引
------解决方案--------------------也不是,比如
select * from a where exists(xxx)。只是在from的时候,每个括号内是要一个结果集,并且要有别名,apply我很少用,不知道有有没有这种限制