sql语句的书

‘壹’ sql语句查询（图书借阅）

1，查询所有借过书的学生编号，姓名，专业，？SELECT DISTINCT borrow.stuid, student.major
FROM borrow LEFT OUTER JOIN
student ON borrow.stuid = student.stuID2，借书但是未归还的学生姓名及该生未归还书的图书数量？SELECT student.stuName, COUNT(1) AS Expr1
FROM borrow LEFT OUTER JOIN
student ON student.stuID = borrow.stuid
WHERE (borrow.b_time IS NULL)
GROUP BY student.stuName3，比如书名是《天龙八部》，请分别查询借过它的人的姓名，借书日期，看了多少天，要考虑若某人借了但是没还，则在看了多久一栏填上（尚未归还）SELECT student.stuName, borrow.t_time, CASE WHEN borrow.b_time IS NULL THEN '尚未归还' ELSE cast(datediff(day,t_time,b_time) as varchar) END AS Expr1
FROM borrow LEFT OUTER JOIN
student ON student.stuID = borrow.stuid LEFT OUTER JOIN
book ON borrow.bid = book.Bid
WHERE (book.title = '天龙八部')