如何在SQL中将不同的值显示为不同的列？

Question

我有一个包含UserID, SiteID, SiteViews列的表和另一个包含UserID, First, Last

的表

我需要将数据显示为First + Last, Site1Views, Site2Views

只有2个站点ID，我需要拥有每个用户SiteView的总和。

目前我有：

select s.UserFirstName + ' ' + s.UserLastName as 'Name', 
j1.SiteViews as 'Site1Name',
j2.SiteViews as 'Site2Name' 
from (Users s INNER JOIN Usage j on s.UserID = j.UserID)

我不知道该怎么做。任何帮助将不胜感激。

Answer 1

听起来你可能想要使用PIVOT吗？我无法测试它，但这应该让你朝着正确的方向前进？

select s.UserFirstName + ' ' + s.UserLastName as Name, 
       [Site1Name],
       [Site2Name]
FROM
       (SELECT s.UserFirstName + ' ' + s.UserLastName,
               SiteName,
               SiteVisits
        from Users s 
        INNER JOIN Usage j1 
          on s.UserID = j1.UserID
       )
PIVOT (SUM(SiteVisits) FOR SiteName IN ([Site1Name],[Site2Name])) as p

Answer 2

我是如何理解的

select s.UserFirstName + ' ' + s.UserLastName as Name 
,(Select COUNT(*) from SiteViews s1 where s.UserID = s1.UserID /*other condition*/) as SiteView1
,(Select COUNT(*) from SiteViews s2 where s.UserID = s2.UserID /*other condition*/) as SiteView2 
from Users s