Question : Left Join Distinct Rows only?

I was just wondering is it possible to do a left join and take the top row only?

My SQL is as follows

select * from orders o
left join user u on u.userId = o.userId
left join invoice i on i.orderId = o.orderID

Which returns 10 rows, but if I remove the last line I get 6 rows. This is because the invoice table holds a reference to the various items placed within an order.

I did think that the left join would only add onto the rows that existed from the select orders, and not append extra rows. Anyway is there a way to limit the join to the Top or Distinct only?


I really am not explaining this well...

Answer : Left Join Distinct Rows only?

you can try to use a subselect in left join:

left join (select distinct from table where something) tab1 on something

sorry i don't really understand your explanation, i hope at least this will be a small clue..