如何在另一个表中具有相同值的SQL表中选择第一行和第二行实例？

Question

示例数据：

输出应为：

我想问一下MSSQL中我可以运行什么脚本来获得那种输出。希望有人可以帮助我，我仍然是SQL编程的新手。非常感谢你。

Answer 1

使用带有row_number（）的CTE：

with CTE as
(
select T1.*, row_number() over(partition by USERNAME order by TRANSACTION_TIME) X_ORD
from Table1 T1
)

select distinct 
       A1.USERNAME,
       A1.REGISTRATION_DATE, 
       A2.Transaction_Time as First_X, 
       A2.RELOAD_AMOUNT as First_R, 
       A2.CHANNEL as First_C, 
       A3.Transaction_Time as Second_X, 
       A3.RELOAD_AMOUNT as Second_R, 
       A3.CHANNEL as Second_C
from CTE A1
left join CTE A2
  on A1.USERNAME = A2.USERNAME
  and A2.X_ORD = 1
left join CTE A3
  on A1.USERNAME = A3.USERNAME
  and A3.X_ORD = 2