如何识别SQL查询是否执行 - How to identify sql query is executed or not?

How to identify sql query is executed or not?

$sql='SELECT sender 
      FROM messages 
      WHERE message_id = :message_id';
$sender_result = $db->query($sql, array(':message_id'=>$message_id));
$sender = $sender_result->fetch();

我用它来执行上面的sql。如何在If中使用$sender。

尝试将 TRY-CATCH 用作：

try {
   $sql='SELECT sender 
      FROM messages 
      WHERE message_id = :message_id';
   $sender_result = $db->query($sql, array(':message_id'=>$message_id));
   $sender = $sender_result->fetch();
} catch(PDOException $ex) {
    // handle exception by using your own logic
    echo "An Error occured!"; //a custom error message
    your_logging_function($ex->getMessage());
}

这是您可以测试的最简单方法

$query = $DB->query(".....");
if($query) // will return true if succefull else it will return false
{
// code here
}

if(isset($sender[0]))){
            return TRUE;
        }
        else {
            return FALSE;
        }