sql查詢學生總?cè)藬?shù) 怎樣用SQL語句表示:查詢每個班級的學生人數(shù)?
怎樣用SQL語句表示:查詢每個班級的學生人數(shù)?SELECT Cno,COUNT(*) AS 人數(shù) --統(tǒng)計FROM StudentsGROUP BY Cno -- 分組 關于SQL查詢,有學生和班級兩
怎樣用SQL語句表示:查詢每個班級的學生人數(shù)?
SELECT Cno
,COUNT(*) AS 人數(shù) --統(tǒng)計
FROM Students
GROUP BY Cno -- 分組
關于SQL查詢,有學生和班級兩張表。查詢班級人數(shù)大于50的班級的所有信息?
SELECT 班級.ID FROM 班級, 學生 WHERE 班級.ID = 學生.所屬班級ID GROUP BY 班級.ID HAVING COUNT(學生.ID) > 50 上面的SQL, 只獲取班級人數(shù)大于50的班級的 ID 如果要班級的所有信息 SELECT * FROM 班級 WHERE 班級.ID IN ( SELECT 班級.ID FROM 班級, 學生 WHERE 班級.ID = 學生.所屬班級ID GROUP BY 班級.ID HAVING COUNT(學生.ID) > 50 )
有學生和班級兩張表,如何用一條sql語句查詢學生人數(shù)最多的班級信息?
select * from 班級 a left join (select 班級id,count(*) as counta from 學生 group by 班級id) b on a.班級id=b.班級idwhere b.counta=(select top 1 COUNT(*) as counta from StudioNews group by UserID order by counta desc) 可能存在人數(shù)最多的不止一個班級
一張學生成績表內(nèi)SQL查詢每個班級每門課程的平均分?
SQL語句如下: SELECT 學號, Count(課程編號) AS 課程總數(shù), Sum(成績) AS 總分數(shù), Avg(成績) AS 平均分 FROM 成績表 GROUP BY 學號SQL常用操作語句如下:選擇:select * from table1 where 范圍 插入:insert into table1(field1,field2) values(value1,value2) 刪除:delete from table1 where 范圍 更新:update table1 set field1=value1 where 范圍 查找:select * from table1 where field1 like ’%value1%’ 排序:select * from table1 order by field1,field2 [desc] 總數(shù):select count as totalcount from table1 求和:select sum(field1) as sumvalue from table1 平均:select avg(field1) as avgvalue from table1 最大:select max(field1) as maxvalue from table1 最?。簊elect min(field1) as minvalue from table1
怎樣用SQL語句表示:查詢每個班級的學生人數(shù)?
select班級號,count(*)from學生表groupby班級號不知道您的表是什么樣的
SQL查詢統(tǒng)計每個班的學生人數(shù)?
ORDER BY 2,是你在用SELECT作查詢時,用第二個字段進行排序,例如 select name,age from 表 order by 2,(指按age字段排序) select name,age,score from 表 order by 3(指按score字段排序)