LEFT OUTER JOIN (gives extra rows) problem

Question

I have two tables which I want to join together using a left outer join. However, even though my left table contains only unique values, the right table satisfies the CONDI

Answer 1

Hmm, the query is doing what its supposed to since there are duplicate records (or at least duplicate identifiers) in the right hand table.

To get the effect you want something like:

SELECT * FROM @tb1 LEFT OUTER JOIN (SELECT DISTINCT c2 FROM @tb2) t2 ON @tb1.c1 = t2.c2

If that isn't sufficient you'll need to explain the requirement in a bit more detail.