For the life of me I can not figure out what is going on. One UPDATE works fine, and another with different columns using the same tables, gives me the error Subquery Returns Multiple Rows. Well, it does return multiple rows if I just use the subquery. So does the Update that works. It is my understanding that it HAS to return multiple rows in order to make matches in the where clause and update multiple rows. And anything I have done to try and limit the rows returned in the subquery, gives me another error (Either can’t find the column name, or I ‘can’t update that column’).
This works: UPDATE j256_corkys_products SET ProductID = (SELECT virtuemart_product_id FROM j256_virtuemart_products WHERE j256_virtuemart_products.product_sku = j256_corkys_products.ItemCode)
This doesn’t UPDATE j256_virtuemart_products SET product_available_date = (SELECT eta FROM j256_corkys_products WHERE j256_virtuemart_products.virtuemart_product_id = j256_corkys_products.ProductID)