Returning Query Result - php

Question

So, I'm writing this application in PHP where the user has a "Student's Name" and each user has a unique student name. So, before I go any further with my problem, here is the code
*Note I've already prevented the SQL injections
function hello($username123) {
// Connect to Database //
$host3 = "db";
$username3 = "db";
$password3 = "db";
$db3 = "db";
$con3 = mysqli_connect($host3,$username3,$password3,$db3) or die("Can not connect to Server.");
$query3 = mysqli_query($con3,"SELECT student1 FROM users WHERE username = '$username123'");
$student1name = "$query3";
return $student1name;
So, the person enters the username which the registered before hand and each user has a student name.I start a query which selects student1 and student1 is equal to student1name. Student 1 name is then defnied as query3. When I test it all out, all I get is (null).. Does anyone know the problem? Thank you!

Answer 1

I suspect what you want is something like this:
function hello($username123) {
// Connect to Database //
$host3 = "db";
$username3 = "db";
$password3 = "db";
$db3 = "db";
$con3 = mysqli_connect($host3,$username3,$password3,$db3) or die("Can not connect to Server.");
$query3 = mysqli_query($con3,"SELECT student1 FROM users WHERE username = '$username123'");
while ($row = mysqli_fetch_array($query3))
{
$student1name = $row['student1'];
}
return $student1name;
This will put the contents of the last returned row of your query, column "student1", into the variable $student1name, and return it.

Answer 2

You are not fetching data from result. Try this:
function hello($username123) {
// Connect to Database //
$host3 = "db";
$username3 = "db";
$password3 = "db";
$db3 = "db";
$con3 = mysqli_connect($host3,$username3,$password3,$db3)
if (!$con3)
throw new Exception("Connection error");
$result = mysqli_query($con3,"SELECT student1 FROM users WHERE username = '$username123'");
if ($result)
return $result->fetch_object();
else
throw new Exception("Query error: " . mysqli_error($con3));
}