Question

Below I want to insert values into the database. I want to insert each student within a chosen session(exam).

Now lets say the chosen session is 34, my issue is that lets say a select box contains multiple students who are going to take this assessment like below:

<select name='addtextarea' id='studentadd'  multiple='multiple' size='10'>
<option value='1'>Joe Blogs</option>
<option value='4'>Bill Kite</option>
<option value='6'>Mary Scott</option>
</select>

My question is how can I loop through each student so that it inserts the details for each student in the database so that the db table will look like this below when inserted:

SessionId  StudentId
34         1
34         4
34         6

Below is the code for the insert using mysqli/php:

$studentid = (isset($_POST['addtextarea'])) ? $_POST['addtextarea'] : ''; 
        $sessionid = (isset($_POST['Idcurrent'])) ? $_POST['Idcurrent'] : '';   

        $insertsql = "
        INSERT INTO Student_Session
        (SessionId, StudentId)
        VALUES
        (?, ?)
        ";
        if (!$insert = $mysqli->prepare($insertsql)) {
        // Handle errors with prepare operation here
        }                                           

        $insert->bind_param("ii", $sessionid, $studentid);

        $insert->execute();

        if ($insert->errno) {
        // Handle query error here
        }

        $insert->close();

Answer 1

Just loop the bind_param() and execute(), you only need to do the prepare once:

To prevent inserting zeros, I would also wrap the whole of the prepared statement in something like:

if(isset($_POST['addtextarea']) && is_array($_POST['addtextarea']) && count($_POST['addtextarea']) > 0 && isset($_POST['Idcurrent']))
{
    // we have some data to insert, do the prepared stmt

    $insertsql = "
    INSERT INTO Student_Session
    (SessionId, StudentId)
    VALUES
    (?, ?)
    ";

    if ($insert = $mysqli->prepare($insertsql)) {

        foreach($_POST['addtextarea'] as $studentid)
        {
            $insert->bind_param("ii", $_POST['Idcurrent'], $studentid);

            $insert->execute();

            if ($insert->errno) {
                // Handle query error here
            }
        }

        $insert->close();
    }
    else
    {
        // prepare() call failed - syntax error in query or error with the db
        // Handle errors with prepare operation here
    }
}
else
{
    // post data is missing, show message
}