How do I get the SUM visible? - php

Question

I am new into php and mysql and also on this website. So I hope I do everything good.
I am trying to get the SUM of some values in a column. But I don't see any result of this on the website. I am trying for a week now searched a lot of information and topics but so far no result at all. So I would like to ask a favor to you in the hope someone can see what I do wrong.
This is what I have now.
<?php
$con=mysqli_connect("localhost","user","1234","dbname");
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$res = mysqli_query($con,"SELECT SUM(Bedrag) FROM `Uitdraai` WHERE Datum BETWEEN '2018-01-01' AND '2018-03-01'");
if (FALSE === $res) die("Select sum failed: ".mysqli_error);
$row = mysqli_fetch_row($res);
$sum = $row[0];
mysqli_close($con);
?>
I already tried almost every option also on the following pages but so far no luck. I just get my regular webpage only without the answer.
Get sum of MySQL column in PHP
Single Result From SUM With MySQLi
I will be really thankful!

Answer 1

SELECT SUM(Bedrag) AS value_sum FROM `Uitdraai` WHERE Datum BETWEEN '2018-01-01' AND '2018-03-01;
In the PHP code, try this:
$con=mysqli_connect("localhost","my_user","my_password","my_db");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$result = mysqli_query($con,'SELECT SUM(Bedrag) AS value_sum FROM `Uitdraai` WHERE Datum BETWEEN '2018-01-01' AND '2018-03-01');
$row = mysqli_fetch_assoc($result);
$sum = $row['value_sum'];
echo $sum;
Using PDO (mysql_query is depreciated)
$stmt = $handler->prepare("SELECT SUM(Bedrag) AS value_sum FROM `Uitdraai` WHERE Datum BETWEEN '2018-01-01' AND '2018-03-01");
$stmt->execute();
$row = $handler->fetchAll(PDO::FETCH_OBJ);
$sum = $row->value_sum;
echo $sum;

Answer 2

You should know that mysql_connect is depreciated from php 7 or upper. For this you need to use mysqli or pdo for interacting with the server.
you can try below code for getting sum from the database.
$con = new mysqli("localhost", "my_user", "my_password", "my_db");
$sql = "SELECT SUM(Bedrag) AS value_sum FROM Uitdraai WHERE Datum BETWEEN '2018-01-01' AND '2018-03-01'";
$stmt = $con->query($sql);
if($stmt){
$result = $stmt->fetch_assoc();
echo $result['value_sum'];
}