select sname,avg(grade) from sc,student wherestudent.sno=sc.sno 这句话有没有错,求grade的平均值select sname,avg(grade) from sc,student wherestudent.sno=sc.sno这句话有没有错,求grade的平均值

select sname,avg(grade) from sc,student wherestudent.sno=sc.sno 这句话有没有错,求grade的平均值select sname,avg(grade) from sc,student wherestudent.sno=sc.sno这句话有没有错,求grade的平均值 avg. WHERE S.Sno=SC.Sno AND Cname!=数据结构GROUP BY Sname HAVING AVG(Grade)>80里面的S.Sno=SC.Sno 还有GROUP BY Sname HAVING AVG(Grade)>80 select.where student_id>3 GROUP BY math_mark having AVG(math_mark)>70什么意思啊?GROUP BY math_mark having AVG(math_mark)>70 主要是这一部分 if (pastart = -1) sql.append(select * from(); sql.append(select nid,sname,sdescription,nprice,sif (pastart = -1)sql.append(select * from();sql.append(select nid,sname,sdescription,nprice,simg,(CASE smctag WHEN '0' THEN '有货'WHEN '1' THEN ' sql语句：去掉最大值,去掉最小值,算平均值SELECT AVG(Scores.Score)FROM ScoresWHERE ( ( (Scores.[ID]) = @id)AND (Score < (SELECT MAX(Score) From Scores WHERE Scores.[ID] = @id) )AND (Score > (SELECT MIN(Score) From Scores WHERE Scores.[I 在关键字 'group' 附近有语法错误.select sname from s,scwhere s.sno = sc.snoand sc.grade = nullhaving count(*) >= 2group by sc.sno avg 是什么意思 AVG是什么意思 什么是GRA? GRA是什么意思 Gra 是什么意思? SELECT 查询语句中,共有三个部门：10,20,30,查询哪些雇员的工资高于所在部门的平均工资,请问三个命令的区别正确语句如下： SELECT deptno,ename,sal FROM emp outer WHERE sal>( SELECT avg(sal) 关于数据库Oracle的一道题a.course=b.能通俗点解析吗?select courseid as 课程ID,course as 课程名称,nvl(avg(grade),0) as 平均成绩,(select count(grade) from train a where grade Delphi 查询 Access 错误:Field 平均 not foundadoquery1.SQL.Clear;adoquery1.Close;adoquery1.sql.add('select avg(English) as 平均 from Subject');adoquery1.ExecSQL;edit1.Text := adoquery1.Fieldbyname('平均').AsStringadoquery1.sql.add('select MA (select * from student where sname like '王%') 我查出了姓王的,但那非 字 不知道怎么表示了.题目是查表 student中不是姓王的信息 select Student.Sno,Sname,Ssex,Cname,Grade from Student,SC,Course where Student.Sno=SC.Sno and SC.Cnoorder by Student.Sno 用sql server对上述结果做分页显示,我以前没学过对分页不了解,