Question

I need to prepare a SQLite trigger for following condition –

1. There are three tables – retail_store, wholesale_store and product
2. Tables retail_store and wholesale_store have column product_id from table product

Now I want to write a delete trigger such that if a product is deleted from retail_store and if it is not in table wholesale_store, then that product record should be deleted from product table.

** I understand as a practice it may not be a good idea to delete a product record like this. Please take this question only as a technical complication.

Thanks for considering this one. Cheers!

Answer 1

Maybe the following sql statemen is useful for you, but i can’t assure the syntax is correct.

 CREATE TRIGGER after_retail_store_delete after delete ON retail_store
    WHEN ((select count() from  wholesale_store where productid = OLD.id) = 0)
    BEGIN
      DELETE FROM product WHERE productid = OLD.id ;
    END ;