SurrealDB Migrations

An awesome SurrealDB migration tool, with a user-friendly CLI and a versatile Rust library that enables seamless integration into any project.

Warning This project is not production-ready, use at your own risk.

This project can be used:

as a Rust library

cargo add surrealdb-migrations

or as a CLI

cargo install surrealdb-migrations

The philosophy

The SurrealDB Migrations project aims to simplify the creation of a SurrealDB database schema and the evolution of the database through migrations. A typical SurrealDB migration project is divided into 3 categories: schema, event and migration.

A schema file represents no more than one SurrealDB table. The list of schemas can be seen as the Query model (in a CQRS pattern). The schemas folder can be seen as a view of the current data model.

An event file represents no more than one SurrealDB event and the underlying table. The list of events can be seen as the Command model (in a CQRS pattern). The events folder can be seen as a view of the different ways to update the data model.

A migration file represents a change in SurrealDB data. It can be a change in the point of time between two schema changes. Examples are: when a column is renamed or dropped, when a table is renamed or dropped, when a new data is required (with default value), etc...

Get started

 stateDiagram-v2
    scaffold : Scaffold a project
    changeSchema : Change schema/event
    createMigration: Create migration (data changes)
    apply : Apply to your database

    state fork_state <<fork>>
        [*] --> scaffold
        scaffold --> fork_state
        fork_state --> changeSchema
        fork_state --> createMigration

    state join_state <<join>>
        changeSchema --> join_state
        createMigration --> join_state
        join_state --> apply
        apply --> fork_state

1. Scaffold

You can start a migration project by scaffolding a new project using the following command line:

surrealdb-migrations scaffold template empty

This will create the necessary folders and files in order to perform migrations. The empty template should look like this:

/schemas
- script_migration.surql
/events
/migrations

There are a number of pre-defined templates so you can play around and get started quickly.

2. Change schema and/or create data change migrations

Once you have created your migration project, you can start writing your own model. Based on the folders you saw earlier, you can create schema files, event files and migration files.

Schemas

You can create strict schema files that represent tables stored in SurrealDB.

surrealdb-migrations create schema post --fields title,content,author,created_at,status

This will create a schemaless table with predefined fields:

DEFINE TABLE post SCHEMALESS;

DEFINE FIELD title ON post;
DEFINE FIELD content ON post;
DEFINE FIELD author ON post;
DEFINE FIELD created_at ON post;
DEFINE FIELD status ON post;

Events

You can also create events in the same way.

surrealdb-migrations create event publish_post --fields post_id,created_at

This will define a table event with predefined fields:

DEFINE TABLE publish_post SCHEMALESS;

DEFINE FIELD post_id ON publish_post;
DEFINE FIELD created_at ON publish_post;

DEFINE EVENT publish_post ON TABLE publish_post WHEN $before == NONE THEN (
    # TODO
);

Migrations

And when updating data, you can create migration files this way:

surrealdb-migrations create AddAdminUser

This will create a new file using the current date & time of the day, like 20230317_153201_AddAdminUser.surql for example. All migrations files should be listed in a temporal order.

3. Apply to your database

Finally, when you are ready, you can apply your schema and migrations to the database using the following command line:

surrealdb-migrations apply

Or directly inside your Rust project using the following code:

use surrealdb_migrations::MigrationRunner;
use surrealdb::engine::any::connect;
use surrealdb::opt::auth::Root;

#[tokio::main]
async fn main() -> Result<()> {
    let db = connect("ws://localhost:8000").await?;

    // Signin as a namespace, database, or root user
    db.signin(Root {
        username: "root",
        password: "root",
    }).await?;

    // Select a specific namespace / database
    db.use_ns("namespace").use_db("database").await?;

    // Apply all migrations
    MigrationRunner::new(&db)
        .up()
        .await
        .expect("Failed to apply migrations");

    Ok(())
}

4. Repeat

Repeat the process from step 2. Change schema and/or create data change migrations.

Predefined templates

To help you get started quickly, there is a list of predefined templates you can use:

empty - The smallest migration project you can create, a clean schema with an already defined script_migration table to store the applied migrations
blog - A blog domain model, with users having the ability to publish/unpublish posts and comments
ecommerce - An ecommerce domain model, with customers having the ability to purchase products

You can scaffold a project using any of these templates using the following command line:

surrealdb-migrations scaffold template <TEMPLATE>

Configuration

You can create a .surrealdb configuration file at the root of your project. This way you won't have to set the same configuration values every time.

[core]
    path = "./tests-files"
    schema = "less"

[db]
    address = "ws://localhost:8000"
    username = "root"
    password = "root"
    ns = "test"
    db = "test"

In the core section, you can define the path to your schema/migration files, if it is not the current folder.

In the db section, you can define the values used to access your SurrealDB database. It can be the url, username, password, the namespace ns or the name of the database db.

Here is the definition of the .surrealdb configuration file:

[core]
    # Optional
    # Type: String
    # Description: Path to the folder that contains your migration project (root folder by default)
    # Default: "."
    path

    # Optional
    # Type: "less" | "full"
    # Description: Define SCHEMALESS or SCHEMAFULL option by default when creating new table/event file
    # Default: "less"
    schema

[db]
    # Optional
    # Type: String
    # Description: Address of the surrealdb instance
    # Default: "ws://localhost:8000"
    address

    # Optional
    # Type: String
    # Description: Username used to authenticate to the surrealdb instance
    # Default: "root"
    username

    # Optional
    # Type: String
    # Description: Password used to authenticate to the surrealdb instance
    # Default: "root"
    password

    # Optional
    # Type: String
    # Description: Namespace to use inside the surrealdb instance
    # Default: "test"
    ns

    # Optional
    # Type: String
    # Description: Name of the database to use inside the surrealdb instance
    # Default: "test"
    db

Backward migrations

By default, migrations are forward-only. However, it can be interesting to revert a migration in order to undo a mistake. You will find backward migrations in two places:

Inside the /migrations/down folder with the same name as your forward migration
Inside the /migrations but with the .down.surql extension next to the forward migration

So, a migration project with backward migrations might look like this:

/schemas
- script_migration.surql
/events
/migrations
- 20231605_205201_AddProduct.surql
- /down
  - 20231605_205201_AddProduct.surql

Or like this:

/schemas
- script_migration.surql
/events
/migrations
- 20231605_205201_AddProduct.surql
- 20231605_205201_AddProduct.down.surql

If you want to create a DOWN migration file when creating the migration file, use this command:

surrealdb-migrations create AddProduct --down

If you need to, you can revert all migrations back to the one you specified.

surrealdb-migrations apply --down 20231605_205201_AddProduct

And if you need to undo all your migrations, use this command:

surrealdb-migrations apply --down 0

Credits

Inspired by awesome projects:

Roms1383/surrealdb-migrations