//! # sqlx-models
//! sqlx-modes is a work in progress implementation for a sql migration management tool for applications using sqlx. 
//! Beware, this is still under development, and some API's may be broken in the future. 
//! 
//! 
//! 
//! # Basic Tutorial
//! 
//! install the CLI by running the following command: 
//! ```
//! cargo install sqlx-models-cli
//! ```
//! 
//! Now run the following command to create an environment file with the `DATABASE_URL` variable set: 
//! ```
//! echo "DATABASE_URL=sqlite:/database.db" > .env
//! ```
//! We now can create the database running the command: 
//! ```
//! sqlx database create
//! ```
//! This command will have created an sqlite file called `database.db`. 
//! You can now derive the `Models` trait on your structures, 
//! and `sqlx-models` will manage the migrations for you. For example, write at `src/main.rs`: 
//! ```rust
//! #![allow(dead_code)]
//! use sqlx_models::Model; 
//! 
//! #[derive(Model)]
//! struct User {
//!     #[primary_key]
//!     id: i32,
//!     #[unique]
//!     email: String,
//!     password: String,
//!     #[default = 0]
//!     is_admin: bool,
//! }
//! 
//! #[derive(Model)]
//! struct Post {
//!     #[primary_key]
//!     id: i32,
//!     #[foreign_key(User.id)]
//!     author_: String,
//!     #[default = "<UNTITLED POST>"]
//!     title: String,
//!     content: String,
//! }
//! 
//! #[derive(Model)]
//! struct PostLike {
//!     #[foreign_key(User.id)]
//!     #[primary_key(post_id)]
//!     user_id: i32,
//!     #[foreign_key(Post.id)]
//!     post_id: i32,
//! }
//! 
//! #[derive(Model)]
//! struct CommentLike {
//!     #[foreign_key(User.id)]
//!     #[primary_key(comment)]
//!     user: i32,
//!     #[foreign_key(Comment.id)]
//!     comment: i32,
//!     #[default = false]
//!     is_dislike: bool,
//! }
//! 
//! #[derive(Model)]
//! struct Comment {
//!     #[primary_key]
//!     id: i32,
//!     #[foreign_key(User.id)]
//!     author: i32,
//!     #[foreign_key(Post.id)]
//!     post: i32,
//! }
//! fn main() {}
//! ```
//! 
//! If you now run the following command, your migrations should be automatically created.
//! ``` 
//! sqlx generate
//! ```
//! The output should look like this: 
//! ```
//! Generated 1631716729974/migrate user
//! Generated 1631716729980/migrate post
//! Generated 1631716729986/migrate comment
//! Generated 1631716729993/migrate postlike
//! Generated 1631716729998/migrate commentlike
//! ```
//! You can check out the generated migrations at the `migrations/` folder. To commit this migrations you can execute the following command: 
//! ```
//! sqlx migrate run
//! ```
//! The output should look like this: 
//! ```
//! Applied 1631716729974/migrate user (342.208µs)
//! Applied 1631716729980/migrate post (255.958µs)
//! Applied 1631716729986/migrate comment (287.792µs)
//! Applied 1631716729993/migrate postlike (349.834µs)
//! Applied 1631716729998/migrate commentlike (374.625µs)
//! ```
//! If we later modify those structures in our application, we can generate new migrations to update the tables. 
//! 
//! ## Avaibale Attributes
//! ### primary_key
//! It's used to mark the primary key fo the table. 
//! ```rust
//!     #[primary_key]
//!     id: i32, 
//! ```
//! for tables with multicolumn primary keys, the following syntax is used: 
//! ```rust
//!     #[primary_key(second_id)]
//!     first_id: i32, 
//!     second_id: i32, 
//! ```
//! 
//! ### foreign_key
//! It is used to mark a foreign key constraint. 
//! ```rust
//!     #[foreign_key(User.id)]
//!     user: i32, 
//! ```
//! It can also specify `on_delete` and `on_update` constraints: 
//! ```rust
//!     #[foreign_key(User.id, on_delete="cascade"]
//!     user: i32, 
//! ```
//! 
//! ### default
//! It can be used to set a default literal for a column. 
//! ```rust
//!     #[default = 0]
//!     is_admin: bool, 
//! ```
//! 
//! ### unique
//! It is used to mark a unique constraint. 
//! ```rust
//!     #[unique]
//!     email: String, 
//! ```
//! For multicolumn unique constraints the following syntax is used: 
//! ```rust
//!     #[unique(hash)]
//!     username: String,
//!     hash: i32,
//! ```


#[macro_use]
mod error;

mod model;
mod prelude;
mod scheduler;
// mod scheduler;
pub use sqlx_models_proc_macro::Model;

#[doc(hidden)]
pub mod private {
    use once_cell::sync::Lazy;

    pub use super::scheduler::Scheduler;
    pub use super::scheduler::{
        table::{constraint, Column},
        Table,
    };
    pub static MIGRATIONS: Lazy<Scheduler> = Lazy::new(Scheduler::new);
    
    /// Do not use the types defined in this module.
    /// They are intended to be used only through the macro API.
    /// Changes in this module are not considered to be breaking changes.
    pub use super::model::{Dialect, IntoSQL, Model};
}