oracle学习新手，求几条sql的标准答案对照~~~

Posted 2023-05-08

数据中的表格如下：
Employee(EID, Fname, Lname, Address, DOB, Gender, Salary, Bonus, DID)
Department(DID, Name, Mgr_EID, Mgr_Start_Date)
Project(PID, Name, DID)
Work_On(EID, PID, Hours)
PS：DID：Department的ID，DOB：生日。。
SQL 问题：（1）寻找在department中的research department中年龄第二小的。
（2）找出employee里面的名字包含字母"Y"的，并用desending的顺序排列。
（3）找到所有比平均年龄大的employee，列出名字.
(4) 找出每个department所承担的project的数量，并列出department的名字
（5）找出只承担1个project的employee，并列出名字
（6）找出承担大于1个project的employee，列出名字
（7）找出每个employee所承担的project的数量，每个employee的名字要列出
（8）找出男（male)employee和女（female）employee个承担的project的数量
（9）每一个project的有几个employee在做， 要列出project的名字
各位大侠帮忙看下。。。感激不尽~~~，先给100，正确回答了在附加100~~

1、
select EID,Fname from
(select rownum id,E.EID,E.Fname from Employee E,Department D where E.DID=D.DID and D.Name='research' order by DOB desc)
where id=2;
2、
select EID,Fname from Employee where Fname like '%Y%' order by Fname desc;
3、
select Fname from Employee where DOB<(select agv(DOB) from Employee);
4、
select D.DID,D.Name,count(P.PID) from Department D,Project P where D.DID=P.DID group by D.DID,D.Name;
5、
select Fname from
(select E.EID,E.Fname Employee E,Work_On W where E.EID=W.PID group by E.EID,E.Fname having count(W.PID)=1);
6、
select Fname from
(select E.EID,E.Fname Employee E,Work_On W where E.EID=W.PID group by E.EID,E.Fname having count(W.PID)>=1);
7、
select Fname,project数量 from
(select E.EID,E.Fname,count(W.PID) project数量 Employee E,Work_On W where E.EID=W.PID group by E.EID,E.Fname);
8、
select A.EID,A.Fname,A.project数量 maleproject数量,B.project数量 femaleproject数量 from
(select E.EID,E.Fname,count(W.PID) project数量 Employee E,Work_On W where E.EID=W.PID and E.Gender='male' group by E.EID,E.Fname)A,
(select E.EID,E.Fname,count(W.PID) project数量 Employee E,Work_On W where E.EID=W.PID and E.Gender='female' group by E.EID,E.Fname)B;
where A.EID=B.EID;
9、
select P.Name,count(W.EID) Work_On W,Project P where W.PID=P.PID group by P.Name;

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以上，希望对你有所帮助。 参考技术A select Fname from (select top (2) Fname from Employee,Department where Department.name='research '
order by DOB desc) where DOB>ANY(DOB)
SELECT * FROM Employee WHERE Fname like '%Y%'
select Fname from Employee where (sysdate-DOB)>(select avg(sysdate-DOB) from Employee)
select Department.name,count(PID) from Department,Project group by Department.DID
select Fname from Employee where EID in (select EID from Project,Work_On where EID is unique)
select Fname from Employee where Fname not in (select Fname from Employee where EID in (select EID from Project,Work_On where EID is unique))
select Fname,count(PID) from Employee,Project,Work_On
select count(PID),count(select PID from Employee,Project,Work_On)-count(PID) from Employee,Project,Work_On where Gender='male'
select Project.name,count(EID) from Employee,Project,Work_On group by Project.name

oracle开展分组后，取出每组的前几条数据

参考技术A oracle进行分组后，取出每组的前几条数据SELECT *FROM (SELECT 分组的字段名,ROW_NUMBER() OVER(PARTITION BY 分组的字段名 ORDER BY 排序的字段名) AS RNFROM 表名)WHERE RN <= 10�0�2本回答被提问者采纳