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完成 //我的尝试不起作用
SELECT * FROM Placement, Internship WHERE Placement.i_code=Internship.code WHERE Student.f_id <> Internship.f_id
[不能使用 INNER JOIN 和 LEFT JOIN]
关系表:
![关系表][1]
这是你需要的吗?
SELECT Student.* FROM Student, Placement, InterShip WHERE Placement.i_code=Internship.code AND Placement.s_code=Student.id AND Student.f_id <> Internship.f_id
顺便说一句:你为什么不想使用联接?