学生表student(sno,sname,birthday,gender)
课程表course(cid,cname)
成绩表grade(sno,cid,mark)
查询至少有一门课程与sno=1909的学生选择的课程相同的学生的学号和姓名,下列SQL语句中正确的是()
学生表student(sno,sname,birthday,gender)
课程表course(cid,cname)
成绩表grade(sno,cid,mark)
查询至少有一门课程与sno=1909的学生选择的课程相同的学生的学号和姓名,下列SQL语句中正确的是()
SELECT DISTINCT a.sno,a.sname
FROM student a,grade b
WHERE a.sno=1909 and a.sno=b.sno
and b.cid IN (SELECT cid FROM grade WHERE sno=1909)
SELECT DISTINCT a.sno,a.sname
FROM student a,grade b
WHERE a.sno<>1909 and a.sno=b.sno
and b.cid IN (SELECT cid FROM grade WHERE sno=1909)
SELECT DISTINCT a.sno,a.sname
FROM student a,grade b
WHERE a.sno<>1909 and a.sno=b.sno
and b.cid NOT IN (SELECT cid FROM grade WHERE sno=1909)
SELECT DISTINCT a.sno,a.sname
FROM student a,grade b
WHERE a.sno=1909 and a.sno=b.sno
and b.cid IN (SELECT cid FROM grade WHERE sno<>1909)