Question

我需要你的帮助来编写两个SQL查询（DB Oracle）来获取数据。两个表都有大量数据，因此也需要处理性能。以下是场景 -

有两个表Department (DEPT)和Employee (EMP)。他们有 1（DEPT）：M（EMP）的关系。

Department表有列

Row_id, DeptNm, Created_date

Employee表有列

Row_id, EMPName, Emp_num, Par_row_id (FK to DEPT.row_Id), Salary

对于特定的Department，按每个员工的工资降低排序数据并对其进行排名。数据应如下所示：

DeptNm  | EmpNm    | Salary | Rank              
--------------------------------
Finance | Vikram   | 200000 | 1                     
Finance | Uttaam   | 150000 | 2  
Finance | Rajeev   | 100000 | 3  
ITDPPT  | Balaajii | 150000 | 1  
ITDEPT  | Harsha   | 120000 | 2  
ITDEPT  | Weeniji  | 100000 | 3

查询以显示部门的数据最高薪水。数据应为 -

 Dept_Nm   |       EMP_NM |   Salary   
   Finance |   Vikramadit |  2000000  
   ITDEPT  |       Balaji |  1500000

Answer 1

select *
from (
  select dp.deptname,
         emp.empname,
         emp.salary, 
         dense_rank() over (partition by dp.deptname order by emp.salary desc) as rnk
  from employee emp
    join department dp on dp.row_id = emp.par_row_id 
) t
where rnk = 1

Answer 2

试试这个会帮助你把Rank放在我没有得到你想要的过程你想要动态排名而不是尝试任何“临时”变量。

select D.DeptName,E.EmpName,E.Salary from Employee E
lefe join Department as D on D.Par_Row_Id=E.Row_Id order by E.Salaray DESC

Answer 3

select D.DeptName,E.EmpName,E.Salary from Employee E
left join Department as D on D.Par_Row_Id=E.Row_Id order by E.Salaray DESC

请帮助编写SQL查询

3 个答案: