and never use db.Where() with a struct
gorm was seeing a query like
db.Where(Album{Left: left, Right: right})
but if the `left` variable was empty, gorm couldn't differentiate it with an empty field in the struct
so it generated SQL that we weren't expected
like
SELECT * FROM albums WHERE right=?
instead of
SELECT * FROM albums WHERE left=? AND right=?
fixes #230