The book describes how to use the dal left join syntax. Where it talks about inner join, it uses equality test (e.g. db(table1.field1 == table2.field2).select())
However, inside dal.py there is an implementation for an inner join, used like db().select(join=table1.field.on(table2.field)) (i.e., exactly like left join, except it is an inner join) The generated sql uses 'table1 JOIN table2 on (table1.field1 == table2.fields2)' instead of 'WHERE table1.field1 == table2.field2'. It is not documented, and dal test does not test it. What is it useful for? Should it be documented? tested? removed?
