PHP MySQL Query for jQuery Live Search Box – Unable to Output from Different Columns Based on Input Type

I’m fairly new to PHP/MySQL/jQuery and I’m stuck on this one piece of a large project.

Coding a live seach box that I’d like to return Names or Phone Numbers already in the database based on user input. I can get it to output just Names or just Phone Numbers by changing $variable to “Name” or “Phone”, but I’ve been unable to come up with a working solution to dynamically do either sumultaniouly. I’ve been researching/troubleshooting for hours with if/else using is_numeric() and/or is_nan(), setting a global variable, reworking the query many different ways, and done hours of research. Any suggestions are greatly appreciated!

inventory.php:

<?php
// Session Start
session_start();
// If the user not logged in, redirect to the login page
if (!isset($_SESSION['loggedin'])) {
    header('Location: index.html');
    exit;
}

//Connect to database
require_once('connection.php');


if(isset($_REQUEST["term"])){

    $variable = "Name";            

    // Prepare a select statement
    $sql = "SELECT $variable FROM vendor WHERE $variable LIKE ?";

    if($stmt = mysqli_prepare($conn, $sql)){
        // Bind variables to the prepared statement as parameters
        mysqli_stmt_bind_param($stmt, "s", $param_term);
        
        // Set parameters
        $param_term = $_REQUEST["term"] . '%';
        
        // Attempt to execute the prepared statement
        if(mysqli_stmt_execute($stmt)){
            $vendresult = mysqli_stmt_get_result($stmt);
            
            // Check number of rows in the vendresult set
            if(mysqli_num_rows($vendresult) > 0){
                // Fetch vendresult rows as an associative array
                while($row = mysqli_fetch_array($vendresult, MYSQLI_ASSOC)){
                    echo "<p>" . $row["$variable"] . "</p>";
                }
            } else{
                echo "<p>No Match Found - Vendor Setup</p>";
            }
        } else{
            echo "ERROR: Could not able to execute $sql. " . mysqli_error($conn);
        }
    }

    // Close statement
    mysqli_stmt_close($stmt);
}
 
// close connection
mysqli_close($conn);
?>

HEAD portion of inventoryentry.php:

            <script>
                $(document).ready(function(){
                    $('.search-box input[type="text"]').on("keyup input", function(){
                        /* Get input value on change */
                            var inputVal = $(this).val();
                            var vendresultDropdown = $(this).siblings(".vendresult");
                            if(inputVal.length){
                                $.get("backend-search.php", {term: inputVal}).done(function(data){
                                    // Display the returned data in browser
                                        vendresultDropdown.html(data);
                                });
                            } else{
                                vendresultDropdown.empty();
                            }
                    });
    
                    // Set search input value on click of vendresult item
                    $(document).on("click", ".vendresult p", function(){
                    $(this).parents(".search-box").find('input[type="text"]').val($(this).text());
                    $(this).parent(".vendresult").empty();
                    });
                });
            </script>

BODY portion of inventoryentry.php:

<div class="search-box"><input type="text" autocomplete="off" placeholder="Vendor Lookup" /><div class="vendresult"></div></div>

Code does work, but not in the way I’d like.