Support building all types of Statement into string through a trait

[siketyan]

Related thread on Discord: https://discord.com/channels/873880840487206962/1045022584162500728

The problem

SeaORM can query their managed entities using a query generated by SeaQuery, but that needs the following code to be written every time:

let backend = db.get_database_backend();
let statement = Statement::from_string(backend, query.to_string(backend.get_query_builder()));

This is a little complicated, so I am consindering to utilise this, for example:

let backend = db.get_database_backend();
let statement = Statement::from_query(backend, query);

Implementation

To achieve this, we should modify both SeaORM and SeaQuery.

First, *Statement structs such as SelectStatement has a method to_string, but this is not in any trait.
It's ok to just implement the SeaQuery to SeaORM conversion, but SeaORM's dependency to SeaQuery here will be much compilcated.
To avoid this and to help future extensions, I think we should define a new trait in SeaQuery and implement it on *Statement structs:

pub trait IntoQuery {
    pub fn into_query<T: QueryBuilder>(&self, query_builder: T) -> String;
}

Next, we need to add a method on Statement like Statement::from_query.
I am considering the following signature for it:

pub fn from_query<Q: IntoQuery>(db_backend: DbBackend, query: Q) -> Self;

Any idea on this?
I am going to work on this if this idea were agreed from the community and/or contributors.

Thank you for reading!

[billy1624]

Hey @siketyan, thanks for asking!! I think there is a better approach than that?
Check https://www.sea-ql.org/sea-orm-cookbook/003-run-sea-query-statement-on-sea-orm.html

[siketyan]

@billy1624
Oh, I did not notice that 😔 Thank you for suggesting that.
As Stormblessed16 said on Discord, it would be great if that is documented in https://www.sea-ql.org/SeaORM/docs/basic-crud/raw-sql/ or somewhere I think.

[billy1624]

Would you be interested in editing the documentation? An PR would be appreciated!!

[siketyan]

Of course it's okay, I will open a PR later

[billy1624]

Thanks!! @siketyan
Let me know if you need help