我在使用聚合函数和BETWEEN子句获取数据时遇到麻烦

Question

我在使用聚合函数和BETWEEN子句获取数据时遇到了麻烦。

$statusQ = "SELECT COUNT(total_submit_sub) AS noofsub 
            FROM total_noof_sub 
            WHERE sub_name = 'PHP' 
              AND sem = '8'
              AND dept = 'CE'
              AND laborlec = 'Lab'
              AND faculty_name = 'user'
              AND adate BETWEEN '2019/01/01' AND '2019/03/30'";

Answer 1

 $statusQ = "SELECT COUNT(total_submit_sub) AS noofsub 
            FROM total_noof_sub 
            WHERE sub_name = 'PHP' 
              AND sem = '8'
              AND dept = 'CE'
              AND laborlec = 'Lab'
              AND faculty_name = 'user'
              AND convert(DATETIME,adate)   BETWEEN Convert(DATETIME,CASE WHEN isnull(2019/01/01,'')='' THEN adate ELSE isnull(2019/01/01,'') END)     
              AND Convert(DATETIME, CASE WHEN isnull(2019/03/30,'')='' THEN adate ELSE isnull(2019/03/30,'') END) 

请尝试使用此代码， NULL 也是句柄。...

谢谢！！！！！

Answer 2

$statusQ = "SELECT tsid FROM total_noof_sub WHERE sub_name = 'PHP' 
              AND sem = '8'
              AND dept = 'CE'
              AND laborlec = 'Lab'
              AND faculty_name = 'user'
              AND adate BETWEEN '$from_date' AND '$to_date' ";

                    $countnoofsub = mysqli_query($connect, $statusQ);
                    $num_sub = mysqli_num_rows($countnoofsub);

不会。行，我们想要什么。