Erlang PostgreSQL migrations utils

---

Description

Project is based on epgpool and epgsql. It supports sql and erl migrations description.

Usage

1. Create migrations folder (for example, ./migrations)
2. Create migration file with numeric prefix and .erl or .sql extension.
   The prefix must be unique monotonically increasing integer (1,2,3...).
   No dupplicates allowed!

• In case of erl you need to implement dbschema_migration behaviour.
• In case of sql you need to write your sql commands directly.
  And specify -- up and -- down comments to separate "up" migration part from "down"

3. Run dbschema:up(MigrationDir) in you _app.erl start function.
4. To downgrade call dbscheam:down(MigrationDir, PrefixNum)

Sql migration example

./migrations/1-init.sql

-- Up

create table test(
    id serial primary key,
    name text
);

-- Down

drop table test;