hi all,
i’ve got a tricky sql statement to write. is it possible to write a query that performs a join on a column, but will also return rows which don’t join?
the sql for the join is below:
SELECT code,promo_price,c.id,m.months FROM promo_codes AS c
INNER JOIN num_months AS m ON m.`id`=c.`did`
i’m using promo_codes.did as a control column: if it equals 0, then it has a special meaning (num_months = ’all’ in that case). I don’t want to create a new entry in the num_months table for this value though.
i think this could be done with sub-queries perhaps. what i want to say is really:
SELECT code,promo_price,c.id,m.months
FROM promo_codes AS c
INNER JOIN num_months AS m ON m.`id`=c.`did`
OR SELECT * FROM promo_codes WHERE `did` = 0
but this is not valid sql.
has anyone any ideas?
thanks
