Question

场景：我有一个表格Browsers，每次打开浏览器时都会填充相关日期：

BrowserName                Date
-------------------------------------
Firefox?                   8/20/2017
Firefox                    8/20/2017
Google Chrome              8/20/2017
Google Chrome              8/20/2017
Google Chrome              8/20/2017
Opera                      8/20/2017
Internet Explorer          8/20/2017
Internet Explorer          8/20/2017

如果我这样计算：

SELECT
    COUNT (BrowserName) AS [Count Of Uses],
    BrowserName AS [Browser],
    Date
FROM 
    BROWSERS
GROUP BY 
    Date, BrowserName

我得到的结果是这样的：

Count Of Uses       Browser             Date
--------------------------------------------------
       1            Firefox?            8/20/2017
       1            Firefox             8/20/2017
       3            Google Chrome       8/20/2017
       2            Internet Explorer   8/20/2017
       1            Opera               8/20/2017

问题请注意Firefox（Firefox和Firefox?有两个条目。如何将这些组合成Firefox的一个计数，以便我的最终结果如下：

Count Of Uses       Browser             Date
--------------------------------------------------
       2            Firefox             8/20/2017
       3            Google Chrome       8/20/2017
       2            Internet Explorer   8/20/2017
       1            Opera               8/20/2017

感谢。

Answer 1

您可以使用case：

SELECT Date,
       (CASE WHEN BrowserName LIKE 'Firefox%' THEN 'Firefox'
             ELSE BrowserName
        END) as Browser,
       COUNT(*) AS [Count Of Uses]
FROM BROWSERS
GROUP BY Date,
         (CASE WHEN BrowserName LIKE 'Firefox%' THEN 'Firefox'
               ELSE BrowserName
          END) ;

Answer 2

如果您只需要处理这种特殊情况：

SELECT
  COUNT (*) AS [Count Of Uses],
  replace(BrowserName, 'FireFox?', 'Firefox') AS [Browser],
  Date
FROM BROWSERS
GROUP BY 2,3

如果您有多个类似的变体，请嵌套replace()来电话：

replace(replace(BrowserName, 'FireFox?', 'Firefox'), 'Internet Exploder', 'Internet Explorer') AS [Browser]

Answer 3

如果需要处理？一般来说

declare @T table (browser varchar(40), dt date);
insert into @T values 
      ('Firefox?', '8/20/2017')
    , ('Firefox', '8/20/2017')
    , ('Google Chrome', '8/20/2017')
    , ('Google Chrome', '8/20/2017')
    , ('Google Chrome?', '8/20/2017')
    , ('Opera', '8/20/2017')
    , ('Internet Explorer', '8/20/2017')
    , ('Internet Explorer',' 8/20/2017')
    , ('Internet Explorer', '8/21/2017')
    , ('Internet Explorer',' 8/21/2017');
with cte as 
( select t.dt, t.browser  
       , SUBSTRING(REVERSE(t.browser),1,1) as f 
       , case when SUBSTRING(reverse(t.browser), 1, 1) = '?' then substring(t.browser, 1, LEN(t.browser ) -1) else t.browser end as browserT
    from @T t 
) 
select cte.dt as [date], cte.browserT as browswer, count(*) as [count]
from cte
group by cte.dt, cte.browserT 
order by cte.dt, cte.browserT;

SQL：如何将两个单独的值组合成一个计数

3 个答案: