Check if multiple dates are the same in foreach - php

Question

I have an "Events" table in MySQL :
EventsDate('id','event','start_date','end_date')
I'd like to check if multiple events have the same start date to show it differently in my HTML template.
My SQL request is :
SELECT * FROM EVENTSDATE where event='$id' and start_date>='$today' order by start_date asc
Now my foreach :
foreach ($upcomingDates as $value) { //$upcoming is the array with my sql request
}
How can I say : "if you find two rows with the same start_date, echo something"

Answer 1

I have a slightly different approach.
// Array to contain all values
$container = array();
// Loop through your existing array
foreach ($upcomingDates as $key => $value) {
// Check if the value is already in the container array
// If this is the case, its a duplicate.
if (array_key_exists($value['start_date'], $container)) {
$container[$value['start_date']]++;
echo $value.' is a duplicate with key '.$key;
}
// Add each value to the array
$container[$value['start_date']] = 1;
}
Another method is to use array_count_values()
foreach(array_count_values($upcomingDates) as $value => $c) {
if ($c > 1) {
echo $value.' is a duplicate';
}
}
Note that the second option won't work if your $upcomingDates is an array of arrays.

Answer 2

You can make an empty array before the for loop, and add each value in as a key. Then, on each iteration you can check that array for the key, like so:
$values = [];
foreach ($upcomingDates as $value) { //$upcoming is the array with my sql request
if(isset($values[$value])) //duplicate value found
//do something here
$values[$value] = 1;
}

Answer 3

Since you're ordering your events by start_date:
for ($i = 0, $length = count($upcomingDates); $i < $length; $i++) {
$date = $upcomingDates[$i];
if (isset($upcomingDates[$i + 1]) &&
$upcomingDates[$i + 1]['start_date'] == $date['state_date']) {
echo 'this and the next date are equal';
}
}

Answer 4

Try out GROUP BY
look here: GROUP BY

Answer 5

if you want to find duplicates, then you can directly get it from database
ex.
SELECT * FROM EVENTSDATE where event='$id' and start_date>='$today' GROUP BY start_date having count(start_date) > 1 order by start_date asc
or you can find duplicates from resulting array
return only duplicated entries from an array