如何在单个保存按钮上运行多个查询？

Question

When I click on the save button only all_university table updates but the all_colleges table has not been updated. How can I update two tables on one save button?

<?php
  if(isset($_POST['save'])) {
    $chk = implode(",", $_POST['company_name']);  
    $sql = "update all_university set placement = '$chk' where university_name = '".$_POST['university_name']."'";
    $sql = "update all_colleges set placement = '$chk' where college_name = '".$_POST['college_name']."'";
    $value = mysqli_multi_query($link,$sql);
    if($value == true){
        $msg .="<h5 style='color:green'>Successfull</h5>";
    } else {
        $msg .="<h5 style='color:red'>Error!</h5>";
    }
  }
?>

Answer 1

If you want to use the multi-query function, you have to concatenate the two query strings:

$sql = "update all_university set placement = '$chk' where university_name = '".$_POST['university_name']."';";
$sql .= "update all_colleges set placement = '$chk' where college_name = '".$_POST['college_name']."'";

And then execute mysqli_multi_query.

Or, as Rory already mentioned, just query twice using the normal mysqli_query function.

But you should really look into prepared statements as you are vulnerable to SQL injection!