您好我已经为Derby数据库编写了一个SQL查询,该数据库从每个公司中获取最高薪水的员工
这些是表结构
create table Company_Tbl_One(
company_Id int primary key,
company_name varchar(100)
)
create table Employee_Tbl_One(
employee_Id int primary key,
employee_name varchar(100),
company int references Company_Tbl_One
)
alter table Employee_Tbl_One add salary int
insert into Company_Tbl_One values(12,'Facebook Inc');
insert into Company_Tbl_One values(11,'Google Inc');
insert into Company_Tbl_One values(10,'Yahoo Inc');
insert into Company_Tbl_One values(14,'AOL Inc');
insert into EMPLOYEE_TBL_ONE(employee_Id,employee_name,company,salary) values(1, 'Tom Jackson',12,1000);
insert into EMPLOYEE_TBL_ONE(employee_Id,employee_name,company,salary) values(2, 'Jimmy John',12,200);
insert into EMPLOYEE_TBL_ONE(employee_Id,employee_name,company,salary) values(3, 'Samual Jackson',11,2000);
insert into EMPLOYEE_TBL_ONE(employee_Id,employee_name,company,salary) values(4, 'Sam Raime',10,3000);
insert into EMPLOYEE_TBL_ONE(employee_Id,employee_name,company,salary) values(5, 'Tidy Mann',14,5000);
insert into EMPLOYEE_TBL_ONE(employee_Id,employee_name,company,salary) values(6, 'Oliver Stone',14,5300);
insert into EMPLOYEE_TBL_ONE(employee_Id,employee_name,company,salary) values(7, 'Falcon Gonzalies',10,3300);
insert into EMPLOYEE_TBL_ONE(employee_Id,employee_name,company,salary) values(8, 'Ister Jack',11,2300);
sql查询如下
select e.employee_name, c.company_name
from EMPLOYEE_TBL_ONE e,
COMPANY_TBL_ONE c,
(select max(salary) as SALARY,
company as COMPANY_ID
from EMPLOYEE_TBL_ONE group by COMPANY) x
where c.company_Id = x.COMPANY_ID
and e.salary = x.SALARY
and e.company = c.company_Id
现在上面的sql查询工作正常并取出结果,
但是有没有其他方法为同一个问题语句编写SQL查询?
答案 0 :(得分:1)
使用not exists
的另一种方式,即选择另一名薪水较高的员工不存在的所有员工
select e.employee_name, c.company_name, e.salary
from EMPLOYEE_TBL_ONE e
join COMPANY_TBL_ONE c on e.company = c.company_Id
where not exists (
select 1 from EMPLOYEE_TBL_ONE e2
where e2.company = e.company
and e2.salary > e.salary
)
答案 1 :(得分:0)
您可以使用SQL的RANK函数
SELECT *
FROM Company_Tbl_One C
INNER JOIN
(
SELECT *, RANK() OVER(PARTITION BY Company ORDER BY Salary DESC) AS rank
FROM Employee_Tbl_One
) E
ON C.company_Id = E.company
AND E.rank = 1
编辑:对不起,以为是MSSQL