Apply LIMIT And OFFSET Clauses In A MySQL Query To A Specific Table, When The Query Selects Data From Multiple Tables

I'm in the early stages of setting some functionality to control pagination of some image board components with PHP/MySQL.

What I need to do initially is set the LIMIT and OFFSET clauses only on the boards table part of the query. This is so I can paginate by boards displayed.

The images that appear on the boards (4 per board) are controlled by a counter inside a while loop when this data is outputted, so it is important that no LIMIT or OFFSET is applied to those.

The data is fetched with one query to prevent doing nested MySQL calls to the database which would be a performance problem.

There are 3 tables at play in the MySQL below - a boards table, an images table, and a boards_images table that is a pivot/linking table with a many-to-many relationship that stores the images that are allocated to the boards.

Question

In the following function, how would I set it so the LIMIT and OFFSET clauses only apply to the boards table. I can't work out if I need to group the data, or do a subquery, neither of which I have done before, or if the solution is neither of those approaches?

function boardsOutput($limit=0, $offset=0) {

    $s = "SELECT boards.board_name, boards.board_id, boards.user_id, images.filename开发者_如何学编程, images.image_title
    FROM boards
    LEFT JOIN boards_images ON boards_images.board_id = boards.board_id
    LEFT JOIN images        ON boards_images.image_id = images.image_id
    WHERE boards.user_id = :user_id
    ORDER BY boards.board_id DESC";

    // append the LIMIT and OFFSET values onto the query
    if($limit > 0) {
        $s.= " LIMIT " . $limit;
    }
    if($offset > 0) {
        $s.= " OFFSET " . $offset;
    }

    return $s;
}

// Provide values for the $limit and $offset arguments
$queryString = boardsOutput($limit, $offset);

// then add the $queryString variable to a PHP PDO prepare() method etc

Any help hugely appreciated.