Timediff calucate在哪里查询

Question

我有一个查询，我计算每个用户的工作时间。

$sql = "
SELECT actief
     , userid
     , DATE_FORMAT(datum, '%x - %V')
     , username
     , min_urenperweek
     , SEC_TO_TIME(SUM(TIME_TO_SEC(tijd_tot) - TIME_TO_SEC(tijd_van))) timediff
  FROM " . TBL_URENREGISTRATIE . " ur
  JOIN " . TBL_CMS_USERS . " us 
    ON us.userid = ur.userid
 GROUP 
    BY YEARWEEK(datum)
     , userid 
 ORDER 
    BY us.username ASC
    " ;

我想要的是：如果min_urenperweek让它说40小时而timediff超过40小时，我不希望它显示它是否小于40然后我想显示它

我尝试了Where min_urenperweek <= timediff，但它不起作用

Answer 1

1. GROUP BY子句中的字段应与SELECT子句中不属于聚合函数的字段相同。

2. 您无法在SELECT子句中的WHERE子句中指定别名。

3. 如果要过滤聚合的结果，则不能在WHERE子句中执行此操作，为此目的存在HAVING子句

尝试这样的事情

$sql = "
SELECT actief
     , userid
     , DATE_FORMAT(datum, '%x - %V')
     , username
     , min_urenperweek
     , SEC_TO_TIME(SUM(TIME_TO_SEC(tijd_tot) - TIME_TO_SEC(tijd_van))) timediff
  FROM " . TBL_URENREGISTRATIE . " ur
  JOIN " . TBL_CMS_USERS . " us 
    ON us.userid = ur.userid
 GROUP 
    BY actief
     , userid 
     , DATE_FORMAT(datum, '%x - %V')
     , username
     , min_urenperweek   
 HAVING min_urenperweek <= timediff
 ORDER 
    BY us.username ASC
    " ;