Impl TryGetableMany for diffrent types of generices

[MuhannadAlrusayni]

Resolve #174
in addition I implemented TryGetableMany for 4 types tuple, and I think we will need more in the future.

[MuhannadAlrusayni]

wait don't merge this, looks like we need to do the same for TryFromU64 to make #174 work.

[MuhannadAlrusayni]

Done. Waiting for reviews :D

[tyt2y3]

Thank you. Out of curiosity, why do you needed tuple of such high arity?

[MuhannadAlrusayni]

Out of curiosity, why do you needed tuple of such high arity?

In my case I need it to do many-to-many, where 1st table have primary key of Uuid and the 2nd table have primary key of (String, String), and 3rd table (intermediate table) would have primary key of (Uuid, String, String).
I can imagine a use case where 1st table have two columns primary key, and the 2nd table have two columns primary keys.

we can also do this, but I'm not sure if this is useful use case: (I have not tried that yet :D)

let stmt = "select id, name, age, gender from ..";
let res: (i32, String, i32, String) = db.query_one(stmt)?
    .unwrap()
    .try_get_many("", &["id".to_owned(), "name".to_owned(), "age".to_owned(), "gender".to_owned()])?;

[tyt2y3]

Oh interesting.