#5 Unnecessarily-verbose deletion SQL

DELETE FROM `person`
WHERE `id` = (
    SELECT DISTINCT
        `person`.`id`
    FROM `person`
    WHERE `person`.`id` = ?
)

    #[test]
    fn delete_test() {
        let db = PeopleDB::open_path(":memory:").expect("couldn't open test db");

        let id = db
            .people
            .insert(Person {
                name: "person_name".to_string(),
                roles: Default::default(),
            })
            .expect("couldn't insert test person");
        assert!(db.people.by_id(id).expect("couldn't query db").is_some());

        db.people.with(id, &id).delete();

        assert!(db.people.by_id(id).expect("couldn't query db").is_none());
    }

The deletion support added in 9fece07a2b9c68782 is unfortunately not generating particularly good SQL, though it is functional. The following is an example from one of the test cases, reformatted for clarity: ```sql DELETE FROM `person` WHERE `id` = ( SELECT DISTINCT `person`.`id` FROM `person` WHERE `person`.`id` = ? ) ``` this was generated from the following test: ```rust #[test] fn delete_test() { let db = PeopleDB::open_path(":memory:").expect("couldn't open test db"); let id = db .people .insert(Person { name: "person_name".to_string(), roles: Default::default(), }) .expect("couldn't insert test person"); assert!(db.people.by_id(id).expect("couldn't query db").is_some()); db.people.with(id, &id).delete(); assert!(db.people.by_id(id).expect("couldn't query db").is_none()); } ```