Different price on weekdays and weekends - php

Question

I have a table Orders that holds information about the rental date range and the price for a car rental.
The price is given by:
SELECT ROUND((points * (SELECT DATEDIFF('$dateTo', '$dateFrom'))) * 0.95) AS price
$dateTo and $dateFrom are PHP variables that holds the value of a given date range by the user. In others words:
$dateTo = $_POST['date-to'];
$dateFrom = $_POST['date-from'];
So for each day you are given 5% off from the rental price, but I also want to check if the date range goes across a Saturday or a Sunday. If the rental is from Friday to Monday, I want to add an extra 10 points to the total price because the date range includes a Saturday.
Is this possible?

Answer 1

You could use a stored Procedure for that purpose where your query may be nested inside of a Loop to check if it' s Weekday or not.
Alternatively, You could check if the range of Dates has a Weekend within it using PHP like so:
<?php
/**
* FUNCTION THAT CHECKS IF A WEEKEND EXISTS BETWEEN 2 GIVEN DATES
* #param string $startDate
* #param string $endDate
* #return boolean
*/
function dateRangeContainsWeekend($startDate, $endDate) {
$tsDate = strtotime($startDate);
$diff = date_diff(date_create($startDate), date_create($endDate));
$dDiff = $diff->days;
if ($dDiff > 0) {
for ($i = 0; $i < $dDiff; $i++) {
$timeDiff = 24 * 60 * 60 * $i;
$sDate = $tsDate + $timeDiff;
$weekDay = date('w', $sDate);
if (($weekDay == 0 || $weekDay == 6)) {
return ($weekDay == 0 || $weekDay == 6);
}
}
}
return false;
}
// TESTS - - - -
$d1 = "2016-05-02";
$d2 = "2016-05-10";
var_dump( dateRangeContainsWeekend($d1, $d2) ); // DUMPS true
// NOW; IF YOU KNOW THAT THE GIVEN DATES CONTAIN A WEEKEND,
// YOU MAY MODIFY YOUR QUERY TO REFLECT YOUR DESIRES
$factor = "0.95"; //CHOOSE YOUR FACTOR HERE...
$sql = "SELECT ROUND((points * (SELECT DATEDIFF('$dateTo', '$dateFrom'))) * $factor) AS price";