How to enable auto migration in Go?

This article is to enable auto migration in GoLang with integration with GORM in up-down approach.

Create migration CLI

To enable auto migration in Go with GORM install golang-migrate.

• Run following commands:

$ go get -u -d github.com/golang-migrate/migrate/cmd/migrate
$ cd $GOPATH/src/github.com/golang-migrate/migrate/cmd/migrate
$ git checkout $TAG  # e.g. v4.8.0 
$ go build -tags 'postgres' -ldflags="-X main.Version=$(git describe --tags)

• Navigate to your migrate project and find out migrate.exe file.
• Copy migrate.exe and paste it into $GOPATH/bin folder.
• Your migration CLI is ready to use. N.B: [find out the latest version of migrate cmd and replace it]
• Read more about CLI.

Run your first migration.

i.e: migrate create -ext sql -dir db/migrations -digits 7 create_users_table

• migrate command will create a db/migrations folder with to sql ( up/down) file.
• Edit up file. for example-

CREATE TABLE IF NOT EXISTS users(
   user_id serial PRIMARY KEY,
   username VARCHAR (50) UNIQUE NOT NULL,
   password VARCHAR (50) NOT NULL,
   email VARCHAR (300) UNIQUE NOT NULL
);

• Edit down file. for example-

DROP TABLE IF EXISTS users;

• Now let’s install golang-migrate.

$ go get github.com/golang-migrate/migrate

• Configure migration with GORM.

If you prefer a command-line tool over configured code then it’s for you!

• Remove GORM configuration. (If any)

db, err := gorm.Open("postgres", config.ConnectionString)
   // driver, err := postgres.WithInstance(db.DB(), &postgres.Config{})
  //  m, err := migrate.NewWithDatabaseInstance(
   //     "file://db/migrations",
    //    "postgres", driver)
  //  m.Steps(2)

• Run migration script. i.e:

migrate -source file://{migration file path} -database postgres://{user name}:{password}@{db location}/{db name}?sslmode=disable up

• For example:

migrate -source file://db/migrations -database postgres://postgres:648782@localhost:5432/zachai_auction?sslmode=disable up

• Use down for dropping

1. Happy Coding…😍😍😍