Alternatives to an OR on a join

Really liked a solution I saw recently for an alternative to using an OR clause in a join, as in

select t1.blah, t2.blah from t1

inner join t2 on t1.id = t2.id

or t1.id = t2.id2

 

instead, try it like this

 

select t1.blah, t2.blah from t1

inner join t2 on t1.id = t2.id

union

select t1.blah, t2.blah from t1

inner join t2 on t1.id = t2.id2

 

Nice and elegant, I think. I'll have to explain it better later :-)