Three-way full outer join in SQLite

Question

I have three tables with a common key field, and I need to join them on this key. Given SQLite doesn't have full outer or right joins, I've used the full outer join without right join technique on Wikipedia with much success.

But I'm curious, how would one use this technique to join three tables by a common key? What are the efficiency impacts of this (the current query takes about ten minutes)?

Thanks!

Answer 1

If people stumble across this later, I ultimately tried using temporary tables after the first join, and then joined on this temporary table. It became a hassle, so I ultimately switched to PostgreSQL (which has full outer joins).