Insert form data into two database tables - php

Question

I am looking to post data into two database tables from a single form.
My databases are arranged as below:
Database 1 - 'watchlists':
watchlist_id
user_id
name
description
category
Database 2 - 'watchlist_films':
watchlist_id
film_id
My current MySQL query looks like this: $query = "INSERT INTO watchlist_films (watchlist_id, film_id) VALUES ('$watchlist_name['watchlist_id']', '$rt_id') WHERE watchlists ('watchlist_id') = " . $watchlist_name['watchlist_id'];, but I'm not sure if there's got to be some form of INNER JOIN somewhere?
Not sure what other information/code to provide, so I apologise if there's too little detail here, but, if there's anything else which is needed, just drop me a comment and I'll put up anything else which is required. I'm a relative PHP newbie, so apologies if this seems like a really simple question!
Update based on comments:
I have now got half of my query working, and have updated the logic to reflect it. The new query is basically doing the following:
INSERT new Watchlist to 'watchlists' table
SELECT watchlist_id of new Watchlist from 'watchlists' table WHERE watchlist_name = $watchlist_name (name of new Watchlist just created) and user_id = $user_id
INSERT watchlist_id (selected from previous query) AND film_id into 'watchlist_films' table
based on your comments, my queries now look like so:
if ($submit == 'Submit') {
require_once("db_connect.php");
$watchlist_name = clean_string($_POST['watchlist-name']);
$watchlist_description = clean_string($_POST['watchlist-description']);
$watchlist_category = $_POST['watchlist-category'];
$addWatchlist_bad_message = '';
$addWatchlist_good_message = '';
if ($db_server) {
if (!empty($watchlist_name)) {
$watchlist_name = clean_string($watchlist_name);
$watchlist_description = clean_string($watchlist_description);
mysql_select_db($db_database);
// Insert new Watchlist into Watchlist index
$insert_new_watchlist = "INSERT INTO watchlists (user_id, name, description, category) VALUES ('$user_id', '$watchlist_name', '$watchlist_description', '$watchlist_category')";
mysql_query($insert_new_watchlist) or die("Insert failed. " . mysql_error() . "<br />" . $insert_new_watchlist);
// Select new Watchlist ID
$select_new_watchlist = "SELECT watchlist_id FROM watchlists WHERE name = " . $watchlist_name;
$new_watchlist_id = mysql_query($select_new_watchlist) or die("Insert failed. " . mysql_error() . "<br />" . $select_new_watchlist);
// Add film to new Watchlist
$add_new_film = "INSERT INTO watchlist_films (watchlist_id, film_id) VALUES ('$new_watchlist_id', '$rt_id')";
mysql_query($add_new_film) or die("Insert failed. " . mysql_error() . "<br />" . $add_new_film);
$addWatchlist_good_message = '<div class="alert alert-success">Watchlist created successfully!</div>';?>
<script>
$('a.add-watchlist').trigger('click');
</script><?php
}
} else {
$addWatchlist_bad_message = '<div class="alert alert-error">Error: could not connect to the database.</div.';?>
<script>
$('a.add-watchlist').trigger('click');
</script><?php
}
require_once("db_close.php");
}
My query, however, seems to be failing at the SELECT statement, in between adding the new Watchlist to the Watchlist index and adding the film to the newly created Watchlist.

Answer 1

try this
$query1 = "INSERT INTO watchlist_films (watchlist_id, film_id)
VALUES ('" . $watchlist_name['watchlist_id'] . "', '$rt_id')";
$query2= "INSERT INTO watchlists ('watchlist_id')
VALUES (" . $watchlist_name['watchlist_id'] . ")";
$result = mysqli_multi_query($query1, $query2);

Answer 2

You will need to write an INSERT for each table.
$mysqli->query("INSERT INTO watchlist_films (watchlist_id, film_id)
VALUES ('" . $watchlist_name['watchlist_id'] . "', '$rt_id')");
$mysqli->query("INSERT INTO watchlists ('watchlist_id')
VALUES (" . $watchlist_name['watchlist_id'] . ")");