Question

I have 2 almost identical tables like this example:

item_list

store     item      price
-------------------------
store1    SKU2388   200
store1    SKU2377   150

season_list

store     item      price     season_start   season_end
-------------------------------------------------------
store1    SKU2377   100       12/10/10       31/12/10
store1    SKU2310   300       12/10/10       31/01/11

There will be multiple stores, and sometimes with multiple seasonal items specific to some stores that only available once in a time then disappears, and won’t make it to normal items list. There will also be some normal items with promotional price on specific period.

Now, how can I make a compilation of these 2 tables, with all prices from normal items, combined with all seasonal items, and if there are some conflicting items, the query will return the one on season_list and discard those on item_list?

Thank you for your help 🙂

Answer 1

select COALESCE(seasonal.price,normal.price) 
from normal left outer join seasonal 
on normal.id= seasonal.id

column and table name is not what you mentioned but hope to get the idea.

It joins two tables and when the seasonal price in not exists or is null it returns the normal price.