How can I properly insert latest id into table with PHP?

[therocker]

How would I insert the latest known id into a different table? Was thinking LAST_INSERT_ID(), but don't know if it's what I'm looking for.

 

Here is my code.

<?php
$insert1 = $mysqli->query("INSERT INTO table1 (title) VALUES ('$title')");

$insert2 = $mysqli->query("INSERT INTO table2 (last_known, title) VALUES ('$last_id', '$title')");
?>

This is all on 1 page. I wanted to insert the id from table1 before actually querying the insert into table2 so that last_known will have the id that table1 has. My intentions is to use this as a custom message page. When someone creates a message, it should insert all of the data into table1 and at the same exact time, insert into table2 the id from table1. The ids are auto increment and will automatically be inserted. I don't want to define the ids because if I insert the new id into table1, then if someone has the URL with something like http://domain.com/message.php?id=1 would easily not be able to insert their own messages because row 1 already exists.

[boompa]

Assuming the ID of the new record is an AUTO_INCREMENT field, you can use mysqli->insert_id.

[therocker]

Assuming the ID of the new record is an AUTO_INCREMENT field, you can use mysqli->insert_id.

Thanks it worked.