如何总结在PHP中的foreach循环

Question

这是我的代码，我想要字段的总和，但是无法做到这一点，任何人都可以在这方面提供帮助

<?php
     $hostname="localhost";  
     $username="root";  
     $password="";  
     $db = "usman";  

     $dbh = new PDO("mysql:host=$hostname;dbname=$db", $username, $password);  

     foreach($dbh->query("SELECT COUNT(*) as cnt
     FROM ams 
     WHERE empid= {$_SESSION['sess_user_id']} 
     GROUP BY leavetype 
     HAVING leavetype =               
     sum('Absent'), sum('Annual'),sum('Medical'), 
     sum('Casual') , sum('LWOP') ") as  $GrandTotal) 
     {  
           echo "<table ><tr ><td style='border: 0px; ' >" .        
           $GrandTotal['cnt'] . "</td></tr></table>";    
           echo "<br>"; 
     }
?>

Answer 1

HAVING是对分组结果的过滤器，而不是选择任何内容的方法

我想你需要类似的东西

SELECT 
  leavetype, 
  count(*) as cnt
FROM ams 
 where empid= {$_SESSION['sess_user_id']} 
 and leavetype in ('Absent', 'Annual','Medical',  'Casual' , 'LWOP') -- if you want only certain leave types
GROUP BY leavetype

如果您只想计算所有这些休假类型的数量，就可以

SELECT 
 count(*) as cnt
FROM ams 
where empid= {$_SESSION['sess_user_id']} 
and leavetype in ('Absent', 'Annual','Medical',  'Casual' , 'LWOP')