migrate

Documentation

Index

• Variables
• func Migrate(c *config.Config, log bool, steps int) error
• func MigrateCLIWrapper(ctx *cli.Context) error
• func MysqlDSN(addr, user, password, dbName string) string
• func Version(db *sql.DB) (int, error)

Variables

var Command = &cli.Command{
	Name:  "migrate",
	Usage: "Run database migrations",
	Subcommands: []*cli.Command{
		{
			Name: "new",
			Action: func(ctx *cli.Context) error {
				folder, err := os.Open("./migrations/")
				if err != nil {
					return err
				}
				files, err := folder.Readdirnames(0)
				if err != nil {
					return err
				}
				sort.Strings(files)

				last := files[len(files)-1]
				n := strings.Index(last, "_")
				if n < 0 {
					return errors.New("no underscore found in last filename")
				}
				lastVersion, err := strconv.Atoi(last[0:n])
				if err != nil {
					return err
				}

				scanner := bufio.NewScanner(os.Stdin)
				fmt.Print("New migration name: ")
				scanner.Scan()
				name := strings.TrimSpace(scanner.Text())
				if name == "" {
					return errors.New("migration name cannot be empty")
				}
				newVersion := strconv.Itoa(lastVersion + 1)
				for i := len(newVersion); i < 4; i++ {
					newVersion = "0" + newVersion
				}
				name = newVersion + "_" + strings.ToLower(strings.ReplaceAll(name, " ", "_"))
				newFiles := []string{name + ".down.sql", name + ".up.sql"}
				for _, name := range newFiles {
					file, err := os.Create("./migrations/" + name)
					if err != nil {
						return err
					}
					if err := file.Close(); err != nil {
						return err
					}
				}
				fmt.Print("Created migration!")
				return nil
			},
		},
		{
			Name:  "run",
			Usage: "Run database migrations",
			Flags: []cli.Flag{
				&cli.Int64Flag{
					Name:  "steps",
					Usage: "Migrations steps to run (0 runs all migrations, and value can be negative)",
				},
			},
			Action: MigrateCLIWrapper,
		},
	},
}

var (
	ErrMigrationsTableNotFound = errors.New("migrations table not found")
)

Functions

func Migrate

func Migrate(c *config.Config, log bool, steps int) error

If steps is 0, all migrations are run. Otherwise, steps migrations are run up or down depending on steps > 0 or not.

func MigrateCLIWrapper

func MigrateCLIWrapper(ctx *cli.Context) error

func MysqlDSN

func MysqlDSN(addr, user, password, dbName string) string

MysqlDSN returns a DSN that could be used to connect to a MySQL database. You may want to append mysql:// to the beginning of the returned string.

func Version

func Version(db *sql.DB) (int, error)

Version returns the last migration number (the value in the schema_migrations table). If the migrations table is not found, then errMigrationsTableNotFound is returned. If the migrations table is found but empty, then sql.ErrNoRows is returned.