I am using the following code to know where to put my next post:

```
// Create connection
$link = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME);

// Check connection
if($link === false){
    die("ERROR: Could not connect. " . mysqli_connect_error());
}

$sql = "SELECT * FROM `wp_posts` WHERE ID = (SELECT max(ID) FROM `wp_posts`)";
$res = $link->query($sql);
while( $rs = $res->fetch_object() ) {
            echo 'Last ID is: '. $rs->ID .' <br />';
            $lastID = $rs->ID;
        }

// Close connection
mysqli_close($link);

$ID_of_Next_Post = $lastID + 1;
echo 'Next post will go to ID: '. $ID_of_Next_Post .' <br />';

```

The issue I'm facing is that if I make a post that goes into, say, ID = 100 and then I delete that post, the next time this code is called `$lastID` will still equal 100 but the next post will go into 102 (because 101 was taken, even though it has been deleted and is not there anymore).

So how can I change my SQL query to find the NEXT AVAILABLE id so I know where the next post will go?
The ID row is set to auto-increment so it's tempting to not set the ID of the post but I need to know what the ID is so I can set interdependencies in other tables of the database.