華閱文章網求三表聯合查詢的SQL查詢語句
車訊語句：select username,psw from (a1 left join a2 on a1.a1_id=a2.a1_id) left join a3 on a1.a1_id=a3.a1_id 這樣寫： SELECT * AS 姓名， *Name AS 課程， * AS 成績 FROM Students AS S INNER JOIN Score AS C ON (* = *tID) INNER JOIN Course AS CS ON (*ID = *ID 擴展資料：SQL聯合查詢的分類 一、內連接查詢：只查詢左邊表有且右邊表也有的數據，本質上是依據外鍵關系，在笛卡爾積查詢的基礎上過濾出正確的數據。
語句有2種形式： Select * from dept ,emp where *=*_id Select * from dept inner join emp on * =*_id 二、外連接查詢：外連接是用于查詢倆邊一邊有一邊沒有的數據。 三、左外連接查詢：在內連接的基礎上增加上左邊表有而右邊表沒有的數據 語句：Select * from dept join emp on *=*_id 四、右外連接：在內連接的基礎上增加上右邊表沒有的記錄 語句：Select * from dept right join emp on * =*_id。
求三表聯合查詢的SQL查詢語句
車訊語句：select username,psw from (a1 left join a2 on a1.a1_id=a2.a1_id) left join a3 on a1.a1_id=a3.a1_id
這樣寫：
SELECT
* AS 姓名， *Name AS 課程， * AS 成績
FROM Students AS S
INNER JOIN Score AS C ON (* = *tID)
INNER JOIN Course AS CS ON (*ID = *ID
擴展資料：
SQL聯合查詢的分類
一、內連接查詢：只查詢左邊表有且右邊表也有的數據，本質上是依據外鍵關系，在笛卡爾積查詢的基礎上過濾出正確的數據。
語句有2種形式：
Select * from dept ,emp where *=*_id
Select * from dept inner join emp on * =*_id
二、外連接查詢：外連接是用于查詢倆邊一邊有一邊沒有的數據。
三、左外連接查詢：在內連接的基礎上增加上左邊表有而右邊表沒有的數據
語句：Select * from dept join emp on *=*_id
四、右外連接：在內連接的基礎上增加上右邊表沒有的記錄
語句：Select * from dept right join emp on * =*_id
sql語句,三表查詢
select *,*in,isnull(*,0),isnull(*,0),* from t1 aleft join (select sum(num) as chuhuo,date,shangpin from t2 group by shangpin,date) b on *=*in left join (select sun(num) as ruku,date,shangping from t3 ) c on *=*inwhere *=(2007-9-20) and *=(2007-9-20)。
三表查詢sql語句
1、select *,*,*,* from sc a left join student b on *=* where *='2' and * between 85 and 100 order by * desc
2、select *,*,* from sc a left join student b on *=* left join course c on *=* where * like '9500%'
三表聯查的SQL語句
這問題交給我吧，假設學生表叫student，課程表叫class，選課表叫choose 1.三層嵌套的問題 select * from student where * IN (select * from choose where * NOT IN (select * from class where *r='李明')） 2.一個內連接，一個嵌套 select *,avg(*) from student inner join choose on *=* where * IN (select * from choose where *<'60' group by * having count(*)>=2) gruop by * 3.一個聯合查詢，一個嵌套查詢 select * from student where * IN (select * from choose c1 where *='1' union select * from choose c2 where *='2' on *=* ) 4.好吧，看起來很難，其實就是自連接查詢和行列交換的問題 select *, (case * when '1' then * end) as 1號課成績， （case * when '2' then * end） as 2號課成績， from student inner join choose on *=* sc1, student inner join choose on *=* sc2 where *='1' and *='2' and *>* 5.至于你說的insert報錯的問題，我想可能是因為學生ID和課程ID這兩個外鍵有重復的值， 你可以檢查下，實在不行刪除外鍵，插入數據，在這里外鍵對你最后要的結果影響不大。
純手工打造~有幫助記得給分哈。
三表查詢sql
額，1分1題，好廉價啊。
看下下面的代碼吧3)select sno,sname from stu a where *='計算機系' and * IN(SELECT SNO FROM SC WHERE CNO=2)4)SELECT *,*,* FROM STU A,COURSE B,SC C WHERE *>3 AND *<60AND *=* AND *=*;5)SELECT *,*,*,*,* from stu a,sc bwhere *=* and * in（'計算機系'，'機械系'，'管理系'） and *>85;6)select *,*,*,* from stu a,sc b where *=* and *<60;7)select *,*,count(1) from course a,sc b where *=* and *>85 group by *,*8)select *,count(1) from stu a,sc b where *=* and *<60 and *='計算機系' group by *;9)select *,* from stu a,sc b where *=* having avg(score)>85 group by *,*10)select cno,count(1) from sc having count(1)<5 group by cno;11)select *,* from (select *,* from stu a,sc b where *=* and *=2) e,(select *,* from stu c,sc d where *=* and *=3) fwhere *=* and *=*;12)select *,* from stu a where * not in (select sno from sc where score<60);13)select *,*,* from stu a,sc b where *=* and *=2 and *=(select max(score) from sc where cno=2);14)select sno,sname from stu where sno in(select * from (select * from sc where score>85) c, (select * from sc where score<60) dwhere *=*);15)select *,* from stu a where * not in(select sno from sc where sno in (select sno from course where credit<=3));。
三表查詢,求SQl語句
select *,*,*2,*3
from a
left join
(select cc.a_id,* data2,* data3
from (select a_id,data,rank() over (partition by a_id order by data) rn from C) cc
full join (select a_id,data,rank() over (partition by a_id order by data) rn from B) bb
on cc.a_id=bb.a_id and *=*
) t on *=t.a_id and *=*
;
PS：這個有一點點問題，你的C表里面各個等級沒有好壞的排序
建議你建C表的時候加一列序列，或者用1ok,2yes,3well,4no，最后選出來的時候可以屏蔽掉前面的排序數字
sqlserver三表聯查sql語句
假設學生表叫student，課程表叫class，選課表叫choose1.三層嵌套的問題select * from student where * IN (select * from choose where * NOT IN (select * from class where *r='李明')）2.一個內連接，一個嵌套select *,avg(*) fromstudent inner join choose on *=*re * IN (select * from choose where *<'60' group by * having count(*)>=2)gruop by *3.一個聯合查詢，一個嵌套查詢select * from studentwhere * IN(select * from choose c1 where *='1' union select * from choose c2 where *='2' on *=*)4.其實就是自連接查詢和行列交換的問題：select *,(case * when '1' then * end) as 1號課成績，（case * when '2' then * end） as 2號課成績，from student inner join choose on *=* sc1,student inner join choose on *=* sc2where *='1' and *='2'and *>*。
