How to send multiple dates to db?

Question

PHP

Hello. My column is of type DATE. But for some reason php does not process this code correctly:

$from = new DateTime('2016-01-31');
$to   = new DateTime('2016-02-04');
 
$period = new DatePeriod($from, new DateInterval('P1D'), $to);
 
$array_dates = array_map(
    function($item){return $item->format('Y.m.d');},
    iterator_to_array($period)
);

$date_string = implode(',',$array_dates);
mysqli_query($connect, "INSERT INTO `date` VALUES (".$date_string.")");

For some reason, one line with the content 0000-00-00 is filled in the database, although there should be several lines with dates. Why do I get such an error?

Answer 1

php has nothing to do with
DATE - it stores the date value as YYYY-MM-DD. For example, 2008-10-23.
Why did you decide that you can write several dates there separated by commas?
If you have several dates, then there should be several cells with the DATE type.
0000-00-00 is the default value for the DATE type, which is set every time an attempt is made to write heresy there.
However, you can pervert and store dates separated by commas in one cell, but of type STRING

Answer 2

$date_string = "('" . implode("'), ('", $array_dates) . "')";