Could somone tell me how to generate an SQL output where 2 tables are conditionally linked, for the following situation:

There is a stock_in table (where stock is brought in) , and an issues table (where stock is issued). The SQL creates an output for issues of a selected product (from the stock_in), which is linked to the issues table by a join statement on the product_id.

My problem is that output is generated so long as there are records corresponding to the stock_in product_id in the issues table. In case the issues table has no issues corresponding to the product_id, it generates an error.

Thanks a lot

Regards,

Steve.