A database migration tool designed to make schema migrations easy.
As an application evolves, the data flowing inside inevitably evolves along with it. If you have an application that persists the data in a relational database, the way you store the data will probably change over time. Morph is a database migration tool that helps you to apply your migrations. It is written with Go so you can use it from your Go application as well. Read our blog post to learn more about the motivation behind this project.
Morph can be used as a library or a CLI tool.
import (
"context"
"github.com/mattermost/morph"
"github.com/mattermost/morph/drivers/mysql"
"github.com/mattermost/morph/sources/embedded"
)
src, err := embedded.WithInstance(&embedded.AssetSource{
Names: []string{}, // add migration file names
AssetFunc: func(name string) ([]byte, error) {
return []byte{}, nil // should return the file contents
},
})
if err != nil {
return err
}
defer src.Close()
driver, err := mysql.WithInstance(db)
if err != nil {
return err
}
engine, err := morph.New(context.Background(), driver, src)
if err != nil {
return err
}
defer engine.Close()
engine.ApplyAll()To install morph you can use:
go install github.com/mattermost/morph/cmd/morph@latestThen you can apply your migrations like below:
morph apply up --driver postgres --dsn "postgres://user:pass@localhost:5432/mydb?sslmode=disable" --path ./db/migrations/postgres --number 1The migrations files should have an up and down versions. The program requires each migration to be reversible, and the naming of the migration should be in the following form:
0000000001_create_user.up.sql
0000000001_create_user.down.sql
The first part will be used to determine the order in which the migrations should be applied and the next part until the up|down.sql suffix will be the migration name.
The program requires this naming convention to be followed as it saves the order and names of the migrations. Also, it can rollback migrations with the down files.