mysql_num_rows() 期望参数 1 是计数行的资源 [重复]答案

【问题标题】：mysql_num_rows() expects parameter 1 to be resource for count row [duplicate]mysql_num_rows() 期望参数 1 是计数行的资源 [重复]
【发布时间】：2016-04-20 07:10:29
【问题描述】：

我得到一个错误 mysql_num_rows() 期望参数 1 是资源

这是我的代码

$carikomoditas = $_POST['cari'];
$cariquery=mysqli_query($connect,"
    SELECT * 
    FROM komoditassample
    WHERE id='$carikomoditas'
") or die('Error');

$data = mysqli_fetch_array($cariquery);
$res = mysql_num_rows($data);
echo $res;

我也试过mysqli num，但同样的错误

【问题讨论】：

混音mysqli with mysql
$cariquery=mysqli_query($connect,"select* from komoditassample` where id='$carikomoditas'") or die(mysqli_error($connect));`

标签： php sql mysqli

【解决方案1】：

试试这个：

$carikomoditas=$_POST['cari'];
$cariquery=mysqli_query($connect,"select*from komoditassample where id='$carikomoditas'") or die('Error');
$res=mysqli_num_rows($cariquery); // result set

$data=mysqli_fetch_array($cariquery);

echo $res;

【讨论】：

【解决方案2】：

使用mysqli，参数应该是查询

$carikomoditas = $_POST['cari'];
$cariquery = mysqli_query($connect, "select * from komoditassample where id='$carikomoditas'") or die('Error');

$data = mysqli_fetch_array($cariquery);
$res  = mysqli_num_rows($cariquery);
echo $res;

已编辑：更详细

$carikomoditas = isset($_POST['cari']) ? $_POST['cari'] : 0;

if (!empty($carikomoditas))
{
    $cariquery  = mysqli_query($connect, "select * from komoditassample where id='$carikomoditas'") or die('Error');

    $total_rows = mysqli_num_rows($cariquery);

    if ($total_rows > 0)
    {
        $data = mysqli_fetch_array($cariquery);
        /*
        Display the retrieved database content here
        */
    }
    else
    {
    echo 'No record found';
    }

}
else
{
echo 'Error: carikomoditas not valid';
}

【讨论】：

【解决方案3】：

这是正确的答案

$carikomoditas=$_POST['cari'];
    //echo$carikomoditas;
    $cariquery=mysqli_query($connect,"select*from komoditassample where id='$carikomoditas'") or die('Errorororor');
    $res=mysqli_num_rows($cariquery);
    echo $res;

mysqli_num_row 参数必须是 mysqli 查询变量而不是 fetch

【讨论】：