Crate evento_sql_migrator 

SQL database migrations for the Evento event sourcing library.

This crate provides database schema migrations required for storing events, snapshots, and subscriber state in SQL databases. It supports SQLite, MySQL, and PostgreSQL through feature flags.

Features

• sqlite - Enables SQLite database support
• mysql - Enables MySQL database support
• postgres - Enables PostgreSQL database support

All features are enabled by default. You can selectively enable only the databases you need:

[dependencies]
evento-sql-migrator = { version = "1.8", default-features = false, features = ["postgres"] }

Usage

The main entry point is the new function, which creates a Migrator instance configured with all Evento migrations.

use sqlx_migrator::{Migrate, Plan};

// Acquire a database connection
let mut conn = pool.acquire().await?;

// Create the migrator for your database type
let migrator = evento_sql_migrator::new::<sqlx::Sqlite>()?;

// Run all pending migrations
migrator.run(&mut *conn, &Plan::apply_all()).await?;

When using the main evento crate, the migrator is re-exported:

let migrator = evento::sql_migrator::new::<sqlx::Sqlite>()?;

Migrations

The crate includes the following migrations:

• InitMigration - Creates the initial database schema (event, snapshot, subscriber tables)
• M0002 - Adds timestamp_subsec column for sub-second precision timestamps
• M0003 - Drops the snapshot table and extends the event name column length

Database Schema

After running all migrations, the database will contain:

Event Table

Stores all domain events:

Column	Type	Description
id	VARCHAR(26)	Event ID (ULID format)
name	VARCHAR(50)	Event type name
aggregator_type	VARCHAR(50)	Aggregate root type
aggregator_id	VARCHAR(26)	Aggregate root instance ID
version	INTEGER	Event sequence number
data	BLOB	Serialized event data
metadata	BLOB	Serialized event metadata
routing_key	VARCHAR(50)	Optional routing key
timestamp	BIGINT	Event timestamp (seconds)
timestamp_subsec	BIGINT	Sub-second precision

Subscriber Table

Tracks event subscription progress:

Column	Type	Description
key	VARCHAR(50)	Subscriber identifier (primary key)
worker_id	VARCHAR(26)	Associated worker ID
cursor	TEXT	Current event stream position
lag	INTEGER	Subscription lag counter
enabled	BOOLEAN	Whether subscription is active
created_at	TIMESTAMP	Creation timestamp
updated_at	TIMESTAMP	Last update timestamp

Structs

InitMigration

Initial migration that creates the core database schema for Evento.

M0002

Migration that adds sub-second precision to event timestamps.

M0003

Migration that drops the snapshot table and extends the event name column.

Functions

new

Creates a new Migrator instance with all Evento migrations registered.