CODEWITHSUNDEEP
phpsqlmysqli
Nicolas Ibarra
Nicolas Ibarra

Reputation: 13

Why is this function not returning the correct result?

I'm fetching data from database by creating two functions "daySum()" and "yesterdaySum()". When calling those functions it returns correct values, 54000 and 51000 respectively.

Then I put them into variables $day and $yesterday, but when doing variable operation "$day+$yesterday" it prints 0. This won't allow me to create a conditional which is needed for my project.

Can you help me out?

Thanks in advance!

//DEFINING 2 FUNCTIONS: daySum() and yesterdaySum()

function daySum() {
    //connect to database
    require 'connect.php';

    // query
    $query = "SELECT sum(till_amount) FROM Cash ";
    $query .= "WHERE date ='2017-09-05'";
    $result = mysqli_query($connect, $query);

    // fetch
    while($row = mysqli_fetch_assoc($result)) {
        print_r($row["sum(till_amount)"]);
    }
}

function yesterdaySum() {
    //connect to database
    require 'connect.php';

    // query
    $query = "SELECT sum(till_amount) FROM Cash ";
    $query .= "WHERE date ='2017-09-04'";
    $result = mysqli_query($connect, $query);

    // fetch
    while($row = mysqli_fetch_assoc($result)) {
        print_r($row["sum(till_amount)"]);
    }
}

// PUTTING THEM INTO VARIABLE 

$day = daySum(); // sum is 54000
$yesterday = yesterdaySum(); // sum is 51000

    // adding $day plus $yesterday should print 105000
    // and here is the problem...

print($day + $yesterday); // it prints 0

//WHY????

Upvotes: 0

Views: 66

Answers (1)

Death-is-the-real-truth
Death-is-the-real-truth

Reputation: 72299

Your function are just printing things.That's why it's add is not working.

You have to change your code like below (some improvement also which is commented):-

<?php
require 'connect.php'; //don't add multiple time
function daySum() {
    $query = "SELECT sum(till_amount) FROM Cash WHERE date ='2017-09-05'";
    $result = mysqli_query($connect, $query);
    while($row = mysqli_fetch_assoc($result)) {
        return $row["sum(till_amount)"]); //return value
    }
}

function yesterdaySum() {
    $query = "SELECT sum(till_amount) FROM Cash WHERE date ='2017-09-04'";
    $result = mysqli_query($connect, $query);
    while($row = mysqli_fetch_assoc($result)) {
       return $row["sum(till_amount)"]); //return value
    }
}

$day = daySum(); // now $day have value
$yesterday = yesterdaySum(); //now $yesterday have value


print((int)$day + (int)$yesterday); // it will work fine now

Now most easy is to use BETWEEN query:-

<?php
require 'connect.php'; //don't add multiple time
function daySum() {
    $query = "SELECT sum(till_amount) FROM Cash WHERE date BETWEEN '2017-09-04' AND '2017-09-05'";
    $result = mysqli_query($connect, $query);
    while($row = mysqli_fetch_assoc($result)) {
        return $row["sum(till_amount)"]);
    }
}

$day = daySum();

print($day);

Note:- May be it's you homework task, but start learning about prepared statements today on-ward to prevent your query from SQL INJECTION.It's important and necessary.

Upvotes: 1

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