在SQL中分组之前组合结果-CombiningresultsbeforegroupinginSQL

4  

You could do it like this

你可以这样做

SELECT 
  [Gender] = CASE [Title] WHEN 'Mr' THEN 'M' ELSE 'F' END, 
  COUNT(*) as Count
FROM
   Customers c
GROUP BY 
  CASE [Title] WHEN 'Mr' THEN 'M' ELSE 'F' END
ORDER By 
  [Count] DESC

Demo at http://sqlfiddle.com/#!3/05c74/4

演示http://sqlfiddle.com/#!3/05c74/4

1  

You can use CASE to project the new groups for the Titles:

您可以使用CASE为标题投影新组:

SELECT SUM(CASE WHEN Title IN ('Mr') THEN 1 ELSE 0 END) AS Male,
       SUM(CASE WHEN Title IN ('Miss', 'Ms', 'Mrs') THEN 1 ELSE 0 END) AS Female
FROM
   Customers c;

0  

Try this:

SELECT (CASE WHEN c.Title = 'Mr' THEN 'Male' 
             WHEN c.Title IN ('Mrs', 'Miss', 'Ms') THEN 'Female' 
             ELSE 'NA' 
        END) AS title, 
        COUNT(1) AS PeopleCount
FROM Customers c
GROUP BY (CASE WHEN c.Title = 'Mr' THEN 'Male' 
              WHEN c.Title IN ('Mrs', 'Miss', 'Ms') THEN 'Female' 
              ELSE 'NA' 
         END)
ORDER By PeopleCount DESC;