How to store multiple fetch data in a variable and use it in MySql where Clause


In this example we store the multiple fetch data in an array and use the array in MySql where clause to retrive data.

index.php

<?php
$host='localhost';
$username='root';
$password='';
$conn=mysqli_connect($host,$username,$password,"student");
$category = mysqli_query($conn,"SELECT * FROM subcategory");
$category_id = [];
$i=0;
while($db_category  = mysqli_fetch_array($category)) {
    $category_id[]=$db_category["category_id"];
    
}
/* print_r($category_id); */
$category_name= mysqli_query($conn,"SELECT * FROM category where id IN ('" . implode("',' ",$category_id) . "')");
    $i=0;
while($db_category_name  = mysqli_fetch_array($category_name)) {
    echo $db_category_name["category_name"].'<br>';
    
}
?>