Question

用SQL语言找出每个学生超过他自己平均成绩的学号和课

设有关系学生(学号，姓名，年龄，院系)、课程(课程号,课程名,先行课)和选课(学号,课程号,成绩)，试用SQL语言找出每个学生超过他自己平均成绩的学号和课程号
一定要保证答案的正确性，对了再加分！

Answer 1

SELECT dbo.student.id, dbo.student.name, dbo.student.age, dbo.student.class, dbo.curriculum.id AS Expr1, dbo.curriculum.name AS Expr2, dbo.curriculum.Firstclass,
dbo.Elective.score, Table1.avgscore
FROM dbo.student LEFT OUTER JOIN
dbo.Elective ON dbo.student.id = dbo.Elective.id LEFT OUTER JOIN
dbo.curriculum ON dbo.Elective.curriculumid = dbo.curriculum.id RIGHT OUTER JOIN
(SELECT id, AVG(score) AS avgscore
FROM dbo.Elective AS Elective_1
GROUP BY id) AS Table1 ON Table1.id = dbo.student.id AND dbo.Elective.score >= Table1.avgscore

追问

这是神马玩意！表示看不懂