Question

我尝试使用带有倍数参数的select count（*）来获取行数，并使用JSON格式对其进行编码，但我得到了这个：

{"notification":[{"count(*)":0}],"message":[{"count(*)":0}]}

而不是例外：

{"notification":0,"message":0}

这里有页面代码：

session_start();
require_once __DIR__ . '/mysql/Db.class.php';
$bdd = new Db();
$t = array();

$query = $bdd->query("SELECT count(*) FROM notification WHERE id_proprio = :id_proprio AND readed = :readed", array("id_proprio"=> $_SESSION['userid'],"readed"=>"0"));
$query_2 = $bdd->query("SELECT count(*) FROM discussion WHERE id_1 = :uid AND readed = :readed AND notifPour = :uid2 OR id_2 = :uid3 AND readed = :readed2 AND notifPour = :uid4", array(
  "uid"=> $_SESSION['userid'],
  "readed"=>"0",
  "uid2"=> $_SESSION['userid'],
  "uid3"=> $_SESSION['userid'],
  "readed2"=>"0",
  "uid4"=> $_SESSION['userid']
));


$t["notification"] = $query;
$t["message"] = $query_2;

echo json_encode($t);

包括Db类的一部分：

public function query($query,$params = null,$fetchmode = PDO::FETCH_ASSOC)
{
    $query = trim($query);

    $this->Init($query,$params); // INIT IS THE CONNECTION TO DB

    if (stripos($query, 'select') === 0) {
        return $this->sQuery->fetchAll($fetchmode);
    }
    elseif (stripos($query, 'insert') === 0 ||  stripos($query, 'update') === 0 || stripos($query, 'delete') === 0) {
    return $this->sQuery->rowCount(); 
    } else {
        return NULL;
    }
}

如何获得如下的例外结果格式：

{"notification":0,"message":0}

谢谢。

Answer 1

修改您的SQL查询以开始：

SELECT count(*) AS cnt FROM

然后从查询中获取值：

$t["notification"] = $query[0]["cnt"];
$t["message"] = $query2[0]["cnt"];

Answer 2

您的MySQL API返回所有行的数组，每行是一个关联数组，其键是SELECT子句中的标签。您需要从数组中提取值：

 $t["notification"] = $query[0]['count(*)'];
 $t["message"] = $query_2[0]['count(*)'];

如何用select count（*）计算行数

2 个答案: