SQL Server 在视图中添加 Where 子句？答案

【问题标题】：SQL Server Adding a Where clause into a view?SQL Server 在视图中添加 Where 子句？
【发布时间】：2019-01-09 13:38:05
【问题描述】：

我有这样的看法：

ALTER VIEW [dbo].[vw_HoursTakenPerEmployee] AS
SELECT e.[EmployeeID], 
       COALESCE(SUM(hrf.[HoursTaken]), 0) AS HoursTaken
FROM [dbo].[Employee] e LEFT JOIN
     [dbo].[HolidayRequestForm] hrf
      ON e.[EmployeeID] = hrf.[EmployeeID]
GROUP BY e.[EmployeeID];
GO

holidayRequestform 表看起来像这样。

 EmployeeID  | HoursTaken     | YearRequested  | MonthRequested |
 ------------+----------------+ ---------------+----------------+
 1           | 8              | 2018           |06
 1           | 16             | 2019           |01
 2           | 8              | 2019           |01
 3           | 8              | 2018           |01

当我选择视图时，结果如下：

EmployeeID|HoursTaken
----------+----------
 1        |24
 2        |8
 3        |8

但是，我只想查看计算当年（2019 年）的小时数，同时仍保留前几年的记录。

我尝试在视图中插入WHERE YearRequested = YEAR(GETDATE()) 子句，但不确定将其放置在何处。

【问题讨论】：

标签： sql-server date where

【解决方案1】：

答案是这样的

ALTER VIEW [dbo].[vw_HoursTakenPerEmployee] AS
SELECT e.[EmployeeID], 
       COALESCE(SUM(hrf.[HoursTaken]), 0) AS HoursTaken
FROM [dbo].[Employee] e LEFT JOIN
     [dbo].[HolidayRequestForm] hrf
      ON e.[EmployeeID] = hrf.[EmployeeID]
WHERE hrf.YearRequested = YEAR(GETDATE())
GROUP BY e.[EmployeeID];
GO

** 只是您视图名称的提示。给它起一个名字来表示年份过滤器

【讨论】：

感谢您的提示

【解决方案2】：

ALTER VIEW [dbo].[vw_HoursTakenPerEmployee] AS
SELECT e.[EmployeeID], 
       COALESCE(SUM(hrf.[HoursTaken]), 0) AS HoursTaken
FROM [dbo].[Employee] e LEFT JOIN
     [dbo].[HolidayRequestForm] hrf
      ON e.[EmployeeID] = hrf.[EmployeeID]
WHERE YearRequested = YEAR(GETDATE()) 
GROUP BY e.[EmployeeID];
GO

--SQL中的SELECT CLAUSE就是这个顺序

SELECT
Columns
FROM TABLEA 
WHERE 
GROUP BY
ORDER BY

【讨论】：