SQLServer根据日期获得最大时间数据（学习笔记）

SQL SERVER 根据日期获得最大时间数据

• 测试数据
• 解决方案
• • A.先跟据数据排序；在根据用户表字段分组
  • B.取出最大时间数据

A.先跟据数据排序；在根据用户表字段分组

SELECT
ID,
UserAccount,
Report_Name,
Longitude,
Latitude,
CAST(Visit_Time AS DATETIME) AS Visit_Time,
ROW_NUMBER() OVER (PARTITION BY UserAccount ORDER BY CAST(Visit_Time AS DATETIME) DESC) RowIndex
FROM Wechat_Log


B.取出最大时间数据

SELECT * FROM
(
SELECT
ID,
UserAccount,
Report_Name,
Longitude,
Latitude,
CAST(Visit_Time AS DATETIME) AS Visit_Time,
ROW_NUMBER() OVER (PARTITION BY UserAccount ORDER BY CAST(Visit_Time AS DATETIME) DESC) RowIndex
FROM Wechat_Log
)
copys WHERE copys.RowIndex=1