How do i count all the values in a table and echo a some certain value if that value repeats itself certain number of times?

Question

I have a database of reservations that contains all of bookings, now I want to limit the dates if 1 date repeats itself certain number of times (for testing purposes, 5). I made a querry that selects all the dates but figured it just counts all the dates not the dates with same values. How do i make it do that?

$sql2 = "SELECT date FROM tbl_reservations ORDER BY date ASC";
                    $res2 = mysqli_query($conn, $sql2);
                    if($res2==TRUE)
                    {
                        $count2 = mysqli_num_rows($res2); 
                        if($count2>5)
                        {
                            while($rows2=mysqli_fetch_assoc($res2))
                            {
                                $books=$rows2['date']; echo"\"$books\",";}}} ?>

Answer 1

You can write below query to select all dates (which were repeated specific amount of times, for example 5):

SELECT COUNT(date) AS numberofreservations, date FROM tbl_reservations GROUP BY date HAVING numberofreservations >= 5

Then you can check if the entered date is contained in the above selection, it means that date is full.

Answer 2

You'll need to group your reservations by date, and then use the count function to give you the number of records for each date.

SELECT COUNT(date) AS numberofreservations, date FROM tbl_reservations GROUP BY date

It may also be an idea to change the name of the date field to something like reservation_date, since date is a field type, and using that as a field name can lead to confusion (and some database engines will require the field name to be quoted, if it's a reserved word)