Use value classes as ID

Description

To prevent accidental using a wrong id from another entity, SQLDelight could generate an ID class for the primary key. For better performance, it should be a value class, if possible.

// before
val userID = 42
todos.find(id = userID) // compiles, but wrong ID

// after
val userID = User.ID(42)
todos.find(id = userID) // error: expected Todo.ID

With this definition, SQLDelight would generate this classes:

CREATE TABLE user (
id INT NOT NULL PRIMARY KEY
);
CREATE TABLE todo (
id INT NOT NULL PRIMARY KEY,
userID INT NOT NULL,

FOREIGN KEY (userID) REFERENCES user(id)
);

data class User(val id: User.ID) {
    value class ID(val value: Int)
}
data class Todo(val id: Todo.ID, val userID: User.ID) {
    value class ID(val value: Int)
}

BTW fluent-kit, an ORM framework written in Swift, provides this feature: http://github.com/vapor/fluent-kit/ Model file: https://github.com/vapor/fluent-kit/blob/main/Sources/FluentKit/Model/Model.swift

[AlecStrong]

you can do composite primary keys, we have some in cash

[eygraber]

You should be able to do this with custom column types. @JvmInline value class works.