下列查询语句中,错误的是()。
A: SELECT Sno, COUNT(*) FROM SC GROUP BY Sno
B: SELECT Sno FROM SC GROUP BY Sno WHERE COUNT(*)> 3
C: SELECT Sno FROM SC GROUP BY Sno HAVING COUNT(*)> 3
D: SELECT Sno FROM SC GROUP BY Sno
A: SELECT Sno, COUNT(*) FROM SC GROUP BY Sno
B: SELECT Sno FROM SC GROUP BY Sno WHERE COUNT(*)> 3
C: SELECT Sno FROM SC GROUP BY Sno HAVING COUNT(*)> 3
D: SELECT Sno FROM SC GROUP BY Sno
举一反三
- 若要求“查询选修了3门以上课程的学生的学号”,正确的SQL语句是( ) A: SELECT sNo FROM SC GROUP BY sNo WHERE COUNT(*)> 3 B: SELECT sNo FROM SC GROUP BY sNo HAVING COUNT(*)> 3 C: SELECT sNo FROM SC ORDER BY sNo WHERE COUNT(*)> 3 D: SELECT sNo FROM SC ORDER BY sNo HAVING COUNT(*)> 3
- 下列查询语句中,错误的是()。 A: ASELECT Sno, COUNT(*) FROM SC GROUP BY Sno B: BSELECT Sno FROM SC GROUP BY Sno WHERE COUNT(*)> 3 C: CSELECT Sno FROM SC GROUP BY Sno HAVING COUNT(*)> 3 D: DSELECT Sno FROM SC GROUP BY Sno
- 针对学生选课表sc(sno, cno, grade),其中sno为学号,cno为课程号,grade为成绩。以下( )语句可查询选修了两门以上成绩在90分以上课程的学生学号。 A: select sno from sc where grade>90 group by sno having count(cno)>2; B: select sno from sc where grade>90 group by sno having count(*)>2; C: select sno from sc where grade>90 and count(*)>2 group by sno; D: select sno from sc where grade>90 group by sno having count(sno)>2;
- 在学生选课数据库中,查询平均成绩大于等于60分的同学,SQL语句为( ) A: SELECT Sno, AVG(Grade) FROM SC GROUP BY Sno HAVING AVG(Grade)>=60; B: SELECT Sno FROM SC WHERE Grade>=60 GROUP BY Sno; C: SELECT Sno, Grade FROM SC GROUP BY Sno HAVING AVG(Grade)>=60; D: SELECT Sno FROM SC GROUP BY Sno HAVING Grade >=60;
- 在学生选课数据库中,查询平均成绩大于等于60分的同学,SQL语句为( ) A: SELECT Sno, AVG(Grade) FROM SC GROUP BY Sno HAVING AVG(Grade)>=60; B: SELECT Sno FROM SC WHERE Grade>=60 GROUP BY Sno; C: SELECT Sno, Grade FROM SC GROUP BY Sno HAVING AVG(Grade)>=60; D: SELECT Sno FROM SC GROUP BY Sno HAVING Grade >=60;