How to fix non response mysql connection in PHP - php

Question

I am trying to get a variable from a mySQL table into my PHP code. I am using a mysqli_query command. When I try to echo the result, it echos nothing, not even other echo statements.
I have ensured that the $conn is correct and working, and that the Sql query is correct by running it directly in PHPmyAdmin.
<?php
session_start();
include_once("includes/dbh.inc.php");
$UID = $_POST['userIdVariable'];
$UID = $_SESSION['u_uid'];
$balance = "SELECT account_balance FROM `users` WHERE user_uid = \"$UID\"";//this line probably works
$result = mysqli_query($conn, $balance);
echo "$result";
When I run this code it would output nothing. The right side of the $balance line is a good sql query according to PHPmyadmin. The $UID variable is read in correctly.

Answer 1

You need to use mysqli_fetch function to get result columns out of $result object.
while ($data = mysqli_fetch_assoc($result)) {
printf("%s \n", $data["account_balance"]);
}

Answer 2

Don't use quotation in a field name or table name inside the query.
$balance = "SELECT account_balance FROM users WHERE user_uid = '$UID'";

Answer 3

please check your database connectivity.there could be something missing like database name.
and print your $UID. may be there is no id getting.
to print data use print_r();
and try this:
session_start();
$servername = "localhost";
$username = "username";
$password = "password";
// Create connection
$conn = new mysqli($servername, $username, $password,"databasename");
$UID=1;
$balance = "SELECT account_balance FROM users WHERE user_uid =$UID";
$result = mysqli_query($conn, $balance);
if (mysqli_num_rows($result)) {
while ($row = mysqli_fetch_assoc($result)) {
echo $row['account_balance'];
}
}