redwing

README

Redwing

Simple database migrations for Go

Installation

go get github.com/andrewapj/redwing

Databases

• MySQL

Example usage

var (
//go:embed migrations
migrations embed.FS
)

func main() {
db, err := sql.Open("mysql", "redwing:redwing@tcp(127.0.0.1:3306)/redwing")
if err != nil {
panic("Can't connect to the DB")
}
defer db.Close()

processed, err := redwing.Migrate(db, redwing.MySQL, migrations, &redwing.Options{Logging: true})

if err != nil {
fmt.Printf("Error processing migrations: %v\n", err)
}

fmt.Printf("Processed the following migrations: %v", processed)

• The user is responsible for creating a sql.DB and closing it when appropriate.
• In this example the migrations are stored under migrations/. Any other valid path can be used.
• The Migrate function will return a []int. This contains the numbers representing the migrations successfully processed.
• The Migrate function will also return an error if a migration fails.
• Further examples can be found at redwing_examples

Migrations

Migrations should be stored in the following format:

1.sql
2.sql
3.sql
etc...

• Each migration will be processed sequentially in turn. Any migration that is successfully processed will be returned within the []int

• If the system encounters a migration that can not be processed it will return an error in addition to the processed migrations, if any.

• Migrations that have already been processed are stored in the migration table and will not be repeated.

Migrations table

• Database migrations are stored within the redwing_migrate table.
• This contains two columns:
  • An id related to the sequential number of the migration.
  • A timestamp of when the migration was applied.

Documentation

Index

• Variables
• func Migrate(db *sql.DB, dialect Dialect, f fs.FS, options *Options) ([]int, error)
• func PrintLog(s string, r *Options)
• type Dialect
• type Options

Variables

var ErrDialectNotSupported = errors.New("dialect not supported")

ErrDialectNotSupported is an error returned when a dialect is not supported

Functions

func Migrate

func Migrate(db *sql.DB, dialect Dialect, f fs.FS, options *Options) ([]int, error)

Migrate starts a database migration

func PrintLog

func PrintLog(s string, r *Options)

Types

type Dialect

type Dialect int

Dialect - A supported database dialect

const (
	//MySQL - The MySQL dialect
	MySQL Dialect = iota
)

type Options

type Options struct {
	Logging bool
}

Options allows the user to provide extra optional parameters for the migration