PDO dynamic parameter binding where clause AND between dates

Question

I have a search form with several input fields. 2 of these input fields are dates. If a users fills in the From/To date, all records from/untill that date should be shown; if a users gives 2 dates, all records between these 2 dates should be shown.

This is my working code for the other input fields, but I have no idea how to implement the date constraints. The parameter binding should stay dynamic since we don't know on how many variables the user will search.

<?php   $this->databaseConnection();

$sql = 'SELECT * FROM trips t';
$searchTerms = array_filter($_GET);
$whereClause = array();

foreach($searchTerms as $key=>$value)
{
    //Push values to array
    array_push($whereClause, "t." . $key . "=:" . $key);
}

if(!empty($whereClause))
{       
    $sql .= " WHERE " . implode(" AND ", $whereClause);
}

    if($this->databaseConnection()) {

    $query_search_data = $this->db_connection->prepare($sql);       
    foreach($searchTerms as $key=>$value)
    {
        $query_search_data->bindValue(':' . $key, $value);
    }

    $query_search_data->execute();
    $result = $query_search_data->fetchAll(); ?>

Answer 1

I found the solution.

Unset the date variables (eg unset($searchTerms['fromDate'], $searchTerms['toDate']); ) and add them again at the end of the query.

if (isset($_GET['fromDate']) && !empty($_GET['fromDate'])) {
    $sql .= " AND Date >=:from_date";
}

Hope this can help other people with dynamic parameter binding issues.