MySQL 计数大小写 return 错误计数

Question

我有以下问题：

我有 mysql table 有：

continent,  
country,  
city,  
zip,  
street,  
status (int),  
reason (varchar, can be empty or some text),  
... (some other columns, not required for query)

我想按 country,city,zip,street 计算每个状态的出现次数，但将 status int 映射到文本：

SELECT country,city,zip,street, 
   CASE WHEN (status = '2' AND reason <> '') THEN "BLOCKED" 
        WHEN (status = '2' AND reason='') THEN "DISPUTED"  
        WHEN status = '3' THEN 'EXPIRED' 
        WHEN status = '1' THEN 'ACTIVE' ELSE 'UNKNOWN' 
        END as status, 
    count(*) AS count
FROM people
where continent='Europe'
GROUP BY country,city,zip,street,status

我认为问题出在 GROUP BY 但不确定 - 它 return 不正确的数据。

SQLFiddle （检查 Paris/Street2 - 它显示 3 DISPUTED，应该显示 1 BLOCKED 和 2 DISPUTED）

感谢意见。

Answer 1

我认为 EngineerCoder 打算写:

select country,city,zip,street, status, count(*) 
from
(
SELECT country,city,zip,street, 
   CASE WHEN (status = '2' AND reason <> '') THEN "BLOCKED" 
        WHEN (status = '2' AND reason='') THEN "DISPUTED"  
        WHEN status = '3' THEN 'EXPIRED' 
        WHEN status = '1' THEN 'ACTIVE' ELSE 'UNKNOWN' 
   END as status, 
FROM people
where continent='Europe'
) AS ilv
GROUP BY country,city,zip,street,status

MySQL 计数大小写 return 错误计数

MySQL count with case return wrong count

mysql

case