RDB Migrations

glim-migrations

glim-migrations is an extension of glim framework for bringing up rdb migrations. An rdb migrations can be defined as a change in the database of an application.

Installation

Shell

# install glim-extensions from pip
pip install glim-extensions

Configuration

Python

config = {
    'extensions' : {
        'migration' : {
            'db' : 'default' # the connection alias
        }
    },

    'db' : {
        'default' : {
            'driver' : 'mysql',
            'host' : 'localhost',
            'schema' : 'test',
            'user' : 'root',
            'password' : ''
        }
    }

    # it is required to have at least one db connection
}

Initializing Migration Extension

Shell

glim migration:init
# this will create a glim_migrations table using rdb connection
# also, it will create app/migrations.py file

Syncing models into db

Suppose that you have the following model in your models;

Python

# app/models.py
from glim.db import Model
from sqlalchemy import Column, Integer, String

class User(Model):
    __tablename__ = 'users'
    id = Column(Integer, primary_key=True)
    name = Column(String(255))
    fullname = Column(String(255))
    password = Column(String(255))

You can easily sync with db using following;

Shell

glim migration:sync --name User
# OR
glim:migration:sync # syncs all your db models

🚧

Won't sync if db table exists

This command will not sync if db table already exists.

Create a migration

Python

# app/migrations.py
from app.models import User
from ext.migration.migration import Migration

class AddUserMigration(Migration):

    description = 'creates a sample user in users table'

    def run(self):
        user = User(id=5, name='Aras')
        self.orm.add(user)
        self.orm.commit()
        return True

    def rollback(self):
        user = self.orm.query(User).filter_by(id=5).first()
        if user is not None:
            self.orm.delete(user)
            self.orm.commit()

To migrate this run the following;

Shell

glim migration:run --name AddUserMigration
# output
# Migrating AddUserMigration..
# Done.

Optionally, you can migrate all with the following command;

Shell

glim migration:run # migrates all defined migrations

This command will add a sample user & add a row into glim_migrations table.

Rollback a migration

Shell

glim migration:rollback --name AddUserMigration
# output
# Rolling back AddUserMigration
# Done.

Optionally, you can rollback all migrations ordered by created_at desc;

Shell

glim migration:rollback # rollbacks all migrations

🚧

Do not change anything in glim_migrations

Please do not change anything in glim_migrations table manually if you don't want the migrations extension to crash.