查询将列分成多列

Question

我有以下情形： 我有2列，第一列称为AgentID，第二列在代理表中称为AgentName。很少AgentID以“A”开头，少数以“M”开头，我想要做的事情如下：

AgentID AgentName 
A123 Name1 
M123 Name2 
A234 Name3 

Aagents AAgentName Magents MAgentName 
A123 Name1  M123 Name2 
A234 Name3  NULL NULL 

这可能吗？我知道这很奇怪，但我的老板想要这样做！

Answer 1

试试这个

WITH AAgents AS 
(
    SELECT ROW_NUMBER() over (order by AgentID) AS RN, 
     AgentID AS Aagents, 
     AgentName As AAgentName 
    FROM Agents 
    WHERE LEFT(AgentID,1)='A' 
), 
MAgents As 
(
    SELECT ROW_NUMBER() over (order by AgentID) AS RN, 
     AgentID AS Magents, 
     AgentName As MAgentName 
    FROM Agents 
    WHERE LEFT(AgentID,1)='M' 
) 

SELECT 
    Aagents, 
    AAgentName, 
    Magents, 
    MAgentName 
FROM AAgents 
FULL OUTER JOIN MAgents 
ON AAgents.RN=MAgents.RN 

SQL FIDDLE DEMO

Answer 2

试试这个

select * from (select AgentID as Aagents, AgentName as AagentName from table where 
AgentID like 'A%'), (select AgentID as MAgents, AgentName as MAgentName from 
table where AgentID like 'M%') 

Answer 3

是这样的：

select 
case when AgentName like 'A%' then name end as Aagents, 
case when AgentName like 'M%' then Name end as Magents 
from tblName 

Answer 4

你可以做一个完整的外部2子查询（一个用于代理，一个对于M代理）之间的连接和加入ROW_NUMBER()在一侧具有空值（具有较少记录的一个）：

select A.AgentID Aagents, A.AgentName AAgentName, M.AgentID Magents, M.AgentName MAgentName from 
(select *, ROW_NUMBER() over (order by AgentID) rn from Agents where AgentID like 'A%') A 
full outer join 
(select *, ROW_NUMBER() over (order by AgentID) rn from Agents where AgentID like 'M%') M 
on A.rn = M.rn