需要解决mysql查询问题

Question

民众

当我运行以下查询时，我得到了无效使用按功能分组的错误

    SELECT `Margin`.`destination`, 
ROUND(sum(duration),2) as total_duration, 
sum(calls) as total_calls 
FROM `ilax`.`margins` AS `Margin` 
 WHERE `date1` = '2013-08-30' and `destination` like "af%"  
AND ROUND(sum(duration),2) like "3%"  
group by `destination` 
ORDER BY duration Asc LIMIT 0, 20;

让我知道围绕

的工作

Answer 1

{<1}}子句在分组发生之前评估，因此WHERE不能在其中使用;请改用SUM()子句，分组后

HAVING

另请注意，实际上应该对数值使用数字比较运算，而不是字符串模式匹配。例如：

SELECT   destination,
         ROUND(SUM(duration), 2) AS total_duration,
         SUM(calls)              AS total_calls
FROM     ilax.margins
WHERE    date1 = '2013-08-30'
     AND destination LIKE 'af%'
GROUP BY destination
HAVING   total_duration LIKE '3%'
ORDER BY total_duration ASC
LIMIT    0, 20