Transforming an Entity into TableCreateStatement

[tyt2y3]

sea-orm/tests/common/setup/schema.rs

Lines 29 to 51 in 08acc2a

	pub async fn create_baker_table(db: &DbConn) -> Result<ExecResult, DbErr> {
	let stmt = sea_query::Table::create()
	.table(baker::Entity)
	.if_not_exists()
	.col(
	ColumnDef::new(baker::Column::Id)
	.integer()
	.not_null()
	.auto_increment()
	.primary_key(),
	)
	.col(ColumnDef::new(baker::Column::Name).string())
	.col(ColumnDef::new(baker::Column::ContactDetails).json())
	.col(ColumnDef::new(baker::Column::BakeryId).integer())
	.foreign_key(
	ForeignKey::create()
	.name("FK_baker_bakery")
	.from(baker::Entity, baker::Column::BakeryId)
	.to(bakery::Entity, bakery::Column::Id)
	.on_delete(ForeignKeyAction::Cascade)
	.on_update(ForeignKeyAction::Cascade),
	)
	.to_owned();

To avoid duplication of information, we can actually generate a SeaQuery SchemaStatement entirely from the Entity definition.
It would be useful in 2 scenarios:

1. writing test cases i.e. original model is MySQL but we want to test in SQLite. this is particularly helpful if the migration files are written in raw SQL. we effectively automatically translated from MySQL to SQLite!

2. writing SQLite applications. in this case, apps don't need a separate migration tool. everything should be done by the app itself. so it's actually helpful to automatically bootstrap a SQLite database from an Entity file

[billy1624]

Wow! neat new feature!!

[tyt2y3]

Not a high priority though. Definitely nice to have.
We actually form a full circle after this.

schema discovery -> schema statement -> entity -> schema statement -> database
^                                                                             |
|_____________________________________________________________________________

[billy1624]

First priority is sea-schema lolll

Postgres support!

[tyt2y3]

@scrblue Would you be interested in this task?

[tyt2y3]

Several action items:

1. review & merge the PR
2. make sure there are enough test cases
3. update our documentation on https://www.sea-ql.org/SeaORM/docs/write-test/sqlite#setting-up-database-schema such that we can use the Entity directly, instead of constructing the schema manually