Currently, `innerJoin` doesn't work if the column we're joining on is nullable, even though inner joins like that work fine in plain SQL. For example: ``` SELECT t.*,o.* from things t INNER JOIN owners o ON t.owner_id = o.id ``` where owner_id is nullable will just skip any rows with null owner_id in SQL, but is not supported by `innerJoin`. It would be nice not to have to drop down to less type-safe `sqlQuery` (I already made a runtime bug there that the compiler otherwise could have caught, which instead showed up when meeting with a potential user!)
