<p>I've tried a couple of approaches to update a column in a mySQL database table from another table but am not having any luck. </p>

<p>I read somewhere that version 3.5.2 does not support multi-table updates and I need a code-based solution - is that correct?</p>

<p>If not can anybody point me in the right direction using sql? </p>

<pre><code>UPDATE products SET products_ordered = (
    SELECT SUM(products_quantity) 
    FROM orders_products 
    WHERE products_id = products.products_id
);
</code></pre>

<p>or:</p>

<pre><code>Create temporary table my_temp_table
as
SELECT products_id, SUM(products_quantity) as total 
FROM orders_products 
GROUP BY products_id 

UPDATE products, my_temp_table
SET products.products_ordered = my_temp_table.total 
WHERE products.products_id = my_temp_table.products_id
</code></pre>

Multi-table updates are not support in MySQL <= 4.0.4
I would highly recommend to update your server to MySQL 5.0.xx