migrations

README

hb migrations - A Better migration engine for go-pg/pg

Basic Commands

• init
  • runs the specified intial migration as a batch on it's own.
• migrate
  • runs all available migrations that have not been run inside a batch
• rollback
  • reverts the last batch of migrations.
• create name
  • creates a migration file using the name provided.

Usage

Make a main.go in a migrations folder

package main

import (
	"flag"
	"fmt"
	"log"
	"os"

	"github.com/go-pg/pg/v10"
	migrations "github.com/hbarnardt/hb_migrations"
)

const usageText = "Lorem Ipsum"

func main() {
	flag.Usage = usage
	flag.Parse()

  dbCnf := ...

	db := pg.Connect(&pg.Options{
		Addr:     dbCnf.GetHost(),
		User:     dbCnf.GetUsername(),
		Database: dbCnf.GetDatabase(),
		Password: dbCnf.GetPassword(),
	})

	migrations.SetMigrationTableName("public.migrations_home")
	migrations.SetInitialMigration("000000000000_init")
	migrations.SetMigrationNameConvention(migrations.SnakeCase)

	err := migrations.Run(db, flag.Args()...)

	if err != nil {
		log.Print(err)
		os.Exit(1)
	}
}

func usage() {
	fmt.Printf(usageText)
	flag.PrintDefaults()
	os.Exit(2)
}

Compile it:

$> go build -i -o ./migrations/migrations ./migrations/*.go

Run it:

$> ./migrations/migrations migrate

Notes on generated file names

$> ./migrations/migrations create new_index

Creates a file in the ./migrations folder called 20181031230738_new_index.go with the following contents:

package main

import (
	"github.com/go-pg/pg/v10"
	migrations "github.com/hbarnardt/hb_migrations"
)

func init() {
	migrations.Register(
		"20181031230738_new_index",
		up20181031230738NewIndex,
		down20181031230738NewIndex,
	)
}

func up20181031230738NewIndex(tx *pg.Tx) error {
	_, err := tx.Exec(``)
	return err
}

func down20181031230738NewIndex(tx *pg.Tx) error {
	_, err := tx.Exec(``)
	return err
}

Forward migration sql commands go in up and Rollback migrations sql commands go in down

Documentation

Index

• func Register(name string, up, down func(*pg.Tx) error)
• func Run(db *pg.DB, cmd string, options ...string) error
• func SetInitialMigration(migrationName string)
• func SetMigrationNameConvention(convention MigrationNameConvention)
• func SetMigrationTableName(tableName string)
• type MigrationNameConvention

Functions

func Register

func Register(name string, up, down func(*pg.Tx) error)

func Run

func Run(db *pg.DB, cmd string, options ...string) error

Run Runs the specified command with the options they require Note:

init - no options
migrate - one option
	- "" for all migrations in a single batch
	- "one-by-one" for one migration in a batch mode
rollback - no options
create - two options
	- name - name of the migration (must be first)
	- template - string that contains the go code to use as a template. see migrationTemplate

func SetInitialMigration

func SetInitialMigration(migrationName string)

func SetMigrationNameConvention

func SetMigrationNameConvention(convention MigrationNameConvention)

func SetMigrationTableName

func SetMigrationTableName(tableName string)

Types

type MigrationNameConvention

type MigrationNameConvention string

const (
	CamelCase MigrationNameConvention = "camelCase"
	SnakeCase MigrationNameConvention = "snakeCase"
)