员工的主要和次要经理[重复]

Question

我想重新组合员工的主要和次要经理：

EmployeeName    ManagerStatus Manager
Mario           Primary       Rodrigo
Mario           Secondary     Thomas

我想做如下的东西：

EmployeeName    PrimaryManager  SecondaryManager
Mario           Rodrigo         Thomas

Answer 1

你想要条件聚合：

select EmployeeName, 
       max(case when ManagerStatus = 'Primary' then Manager end) as PrimaryManager,
       max(case when ManagerStatus = 'Secondary' then Manager end) asSecondaryManager     
from table t
group by EmployeeName;

这假设员工将有一个 primary 或 secondary 经理。

Answer 2

SQL Fiddle

MS SQL Server 2017 架构设置：

create table MyTable(EmployeeName varchar(max),ManagerType varchar(max),Manager varchar(max))
insert into MyTable (EmployeeName,ManagerType,Manager)values
('Mario','Primary', 'Rodrigo'),('Mario','Secondary', 'Thomas')

查询 1：

with CTE AS (select *,
(CASE WHEN ManagerType='Primary' THEN Manager END) AS PrimaryManager,
(CASE WHEN ManagerType = 'Secondary' THEN Manager END) AS SecondaryManager,

ROW_NUMBER() OVER (PARTITION BY ManagerType,Manager

                   Order By EmployeeName DESC) as rn
from MyTable
group by EmployeeName,ManagerType,Manager             )

select c.EmployeeName
,max(c.PrimaryManager) AS PrimaryManager
,max(c.SecondaryManager) AS SecondaryManager

from cte c
where rn=1
group by c.EmployeeName

Results：

| EmployeeName | PrimaryManager | SecondaryManager |
|--------------|----------------|------------------|
|        Mario |        Rodrigo |           Thomas |

Answer 3

你可以试试下面的方法。另一种方法是PIVOT and UNPIVOT。

SELECT EmployeeName
    ,max(PrimaryManager) AS PrimaryManager
    ,max(SecondaryManager) AS SecondaryManager
FROM (
    SELECT EmployeeName
        ,CASE ManagerStatus
            WHEN 'Primary'
                THEN Manager
            END AS PrimaryManager
        ,CASE ManagerStatus
            WHEN 'Secondary'
                THEN Manager
            END AS SecondaryManager
    FROM MyTable
    ) a
GROUP BY EmployeeName

Live Demo