我们不能在PHP中将$ result称为变量

i have query in my php code

$dbc = mysqli_connect('localhost', 'root','', 'delivery')
            or die('Error connecting to MySQL server.');

        $count = "SELECT MAX(id_pelanggan) FROM pelanggan";

        $result = mysqli_query($dbc, $count)
            or die('Error select query');

        if (empty($result)) {
            $id_pelanggan = 1;
        }
        else {
            $id_pelanggan = $result + 1;
        }

and the result was

Object of class mysqli_result could not be converted to int in C:\xampp\htdocs\delivery\addcustomer.php

whereas in mysql id_pelanggan datatype is int. can anyone help me to make it works?

• You try to assign your query to $id_pelanggan variable instead of the value from your query.
• Fetch the result using *_fetch array() of your query
• I've changed your if() condition because your $result won't be empty no matter what happens. The number of result maybe.

Put this and replace your if else condition:

if(mysqli_num_rows($result) == 0){ /* IF FOUND 0 RESULT */
  $id_pelanggan = 1;
}

else {

  while($row = mysqli_fetch_array($result)){
    $maxid = $row["id_pelanggan"];
  }

  $id_pelanggan = $maxid + 1;

} /* END OF ELSE */

Simple fetch the result and increment it. You can do this by -

    $count = "SELECT MAX(id_pelanggan) as max_id_pelanggan FROM pelanggan";

    $result = mysqli_query($dbc, $count)
        or die('Error select query');

    if (empty($result)) {
        $id_pelanggan = 1;
    }
    else {
        $data = mysqli_fetch_assoc($result);
        $id_pelanggan = $data['max_id_pelanggan'] + 1;
    }