三表连接查询sql语句
答：比如有三张表，student，teacher ， project :第一种方法：select * from student,teacher,project where student.id=teacher.sid and student.id=project.sid;第二种：select * from student inner join teacher on student.id=teacher.sid inner join project on student.id=project.sid;...
答：用两个外键关联。比如A,B,C三表进行关联，可以在C表中定义两个外键c1、c2，分别连接到A表和B表的主键a1、b2上，这样只要在查询的时候进行三表联合查询，连接语句为：where C.c1=A.a1 AND C.c2=B.b2；N表查询同上的道理，添加N-1个外键就可以。
答：1) select s.sno,s.sname,s.deptno,g.score from student s,cuorse c,sc g where (s.sno=g.sno) and (c.cno=g.cno) and (c.cno=2) and (g.score beteewn 85 and 100) order by g.score desc,s.sno 2)select c.name from student s,course c,sc g where (s.sno=g.sno...
答：3.一个联合查询，一个嵌套查询 select student.name from student where student.id IN (select c1.sid from choose c1 where choose.cid='1'union select c2.sid from choose c2 where choose.cid='2'on c1.sid=c2.sid )4.其实就是自连接查询和行列交换的问题：select student.id,(case ...
答：3.一个联合查询，一个嵌套查询 select student.name from student where student.id IN (select c1.sid from choose c1 where choose.cid='1'union select c2.sid from choose c2 where choose.cid='2'on c1.sid=c2.sid )4.其实就是自连接查询和行列交换的问题：select student.id,(case ...
答：SELECT 表1.id, 表3.FROM (表1 INNER JOIN 表2 ON 表1.id = 表2.id) INNER JOIN 表3 ON 表2.sid = 表3.sid;
答：--先要确认表也表之间的关系 就是外键关系 如果A表中有B表与C表字段.--这样关系确认.就可以查询到符合这种关系的数据 select * from A表 a,B表 b,C表 c where a.bid=b.bid and a.cid=c.cid 如有问题可以追问，我当及时回答.希望能帮到你！
答：请采用以下sql脚本 select a.partno,c.unitna as [采购单位名称],d.unitna as [主单位名称] from [tb1] as a left join [tb2] as b on a.partno = b.partno left join [tb3] as c on a.setun = c.unitno left join [tb3] as d on b.munit= c.unitno请采纳！
答：1、打开Microsoft SQL Server 2012，选中需要查询所有表的数据库。2、选中需要查询的表后，点击左上角的“新建查询”，如图。3、点击“新建查询”后，会在右边弹出一个编辑框，需要在这里编写sql语句，来查询该数据库下的所有表结构。4、编写sql语句，这表语句可以根据实际情况，来改变条件只查询需要的...
答：SELECT [型号表].[型号]，ISNULL(SUM([领料表].[领用个数]),0) AS [共领料],ISNULL(SUM([入库表].[入库数量]),0) AS [共入库]FROM [型号表]LEFT JOIN [领料表] ON [型号表].[型号] = [领料表].[型号]LEFT JOIN [入库表] ON [型号表].[型号] = [入库表].[型号]GROUP BY...
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卞昭18855716124：
求三表联合查询的SQL查询语句 -
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： 车讯语句: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 这样写: SELECT S.SName AS 姓名, CS.CourseName AS 课程, C.Score AS 成绩 FROM Students AS S INNER JOIN Score AS C ...
卞昭18855716124：
求三表联合查询的SQL查询语句
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： select a.id,a.name,b.name,c.name,a.table2_id,a.table3_id,c.table2_id from table1 a,table2 b,table3 c where a.table2_id=b.id and a.table3_id=c.id and b.id=c.table2_id order by a.id; 以上语句在Oracle11g r2上测试通过,同样可以用于其他数据库,如有疑问请留言
卞昭18855716124：
sql语句查询数据是和三张表有关联的应该怎么写? -
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： select School.SchoolID,Student.StudentName from School full join Class on School.ClassId=Class.ClassId full join Student on Class.StudentId=Student.StudentId要查找的东西放在最上面,然后连接表,连接条件.就这样.
卞昭18855716124：
sql 三表连接查询 -
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： select student.stuno(学号),stuname(姓名),book.bookno(书号),count(amount),sum(price)as 应付 FROM student,book,bookorder where student.stuno=bookorder.stuno,book.bookno=bookorder.bookno group by stuno(学号) go
卞昭18855716124：
sql 3个表的连接查询 -
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： select ml.ml_id,ml.ml_name, dl.dl_name,jd.jd_name,ml.ml_date from ml left join dl on ml.dl_id=dl.dl_id left join jd on ml.jd_id=jd.jd_id
卞昭18855716124：
SQL语句三表连查,急求答案啊.看我详细提问. -
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： select E.id,E.name,E.gender,E.birthday,sum(S.salary),D.deptname from Employee E inner join Salaryrecord S on E.id=S.id and S.sdate>CONVERT(Date,'2012') and S.sdate<CONVERT(Date,'2013') inner join Department D on E.deptid=D.deptid...
卞昭18855716124：
SQL 三表联查 -
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： select t.*,t1.hsdwmc , from a t join b t1 on t1.hsdwmc =t.thsdwmc join c t2 on t.fzmc = t2.fzmc 我上面这样写的需要所有表都有关联才行,如果不是所有表有关联换下面这种写法 select t.*,t1.hsdwmc , t2.fzmc from a t left join b t1 on t1.hsdwmc =t.thsdwmc left join c t2 on t.fzmc = t2.fzmc
卞昭18855716124：
sqlserver三表联查sql语句 -
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： 假设学生表叫student,课程表叫class,选课表叫choose1.三层嵌套的问题 select student.name from student where student.id IN (select choose.sid from choose where choose.cid NOT IN (select class.id from class where class.teacher='李明'))2....
卞昭18855716124：
用SQL语句怎么查询三个表的结果 -
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： select table_a.D,table_a.E,table_b.F (select A.D as D,sum(B.E) as E from A,B where A.D=B.D group by A.D) table_a, (select A.D as D,sum(C.F) as F from A,B where A.D=C.D group by A.D) table_b where table_a.D=table_b.D
卞昭18855716124：
SQL三表连接查询 -
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： select a.*,c.f from (select * from a inner join b on a.a = b.a) as a inner join c on a.d = c.d select a.*,c.f from a inner join b on a.a = b.a inner join b.d = b.d 两个都可以,第一个更容易理解 括号里的部分 是查询出 查询表A的数据和当表A的a=表B的a的数据,把这个结果集 再inner join c on a.d = c.d 查询出表B的d=表C的d 所对应的f的值.
