migration: version 1

+// Beego (http://beego.me/)
+//
+// @description beego is an open-source, high-performance web framework for the Go programming language.
+//
+// @link        http://github.com/astaxie/beego for the canonical source repository
+//
+// @license     http://github.com/astaxie/beego/blob/master/LICENSE
+//
+// @authors     astaxie
+package migration
+
+import (
+	"errors"
+	"sort"
+	"time"
+
+	"github.com/astaxie/beego"
+	"github.com/astaxie/beego/orm"
+)
+
+// const the data format for the bee generate migration datatype
+const M_DATE_FORMAT = "20060102_150405"
+
+// Migrationer is an interface for all Migration struct
+type Migrationer interface {
+	Up()
+	Down()
+	Exec() error
+	GetCreated() int64
+}
+
+var migrationMap map[string]Migrationer
+
+func init() {
+	migrationMap = make(map[string]Migrationer)
+}
+
+// the basic type which will implement the basic type
+type Migration struct {
+	sqls    []string
+	Created string
+}
+
+// implement in the Inheritance struct for upgrade
+func (m *Migration) Up() {
+
+}
+
+// implement in the Inheritance struct for down
+func (m *Migration) Down() {
+
+}
+
+// add sql want to execute
+func (m *Migration) Sql(sql string) {
+	m.sqls = append(m.sqls, sql)
+}
+
+// execute the sql already add in the sql
+func (m *Migration) Exec() error {
+	o := orm.NewOrm()
+	for _, s := range m.sqls {
+		beego.Info("exec sql:", s)
+		r := o.Raw(s)
+		_, err := r.Exec()
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// get the unixtime from the Created
+func (m *Migration) GetCreated() int64 {
+	t, err := time.Parse(M_DATE_FORMAT, m.Created)
+	if err != nil {
+		return 0
+	}
+	return t.Unix()
+}
+
+// register the Migration in the map
+func Register(name string, m Migrationer) error {
+	if _, ok := migrationMap[name]; ok {
+		return errors.New("already exist name:" + name)
+	}
+	migrationMap[name] = m
+	return nil
+}
+
+// upgrate the migration from lasttime
+func Upgrade(lasttime int64) error {
+	sm := sortMap(migrationMap)
+	i := 0
+	for _, v := range sm {
+		if v.created > lasttime {
+			beego.Info("start upgrade", v.name)
+			v.m.Up()
+			err := v.m.Exec()
+			if err != nil {
+				return err
+			}
+			beego.Info("end upgrade:", v.name)
+			i++
+		}
+	}
+	beego.Info("total success upgrade:", i, " migration")
+	return nil
+}
+
+//rollback the migration by the name
+func Rollback(name string) error {
+	if v, ok := migrationMap[name]; ok {
+		beego.Info("start rollback")
+		v.Down()
+		err := v.Exec()
+		if err != nil {
+			return err
+		}
+		beego.Info("end rollback")
+		return nil
+	} else {
+		return errors.New("not exist the migrationMap name:" + name)
+	}
+}
+
+// reset all migration
+// run all migration's down function
+func Reset() error {
+	i := 0
+	for k, v := range migrationMap {
+		beego.Info("start reset:", k)
+		v.Down()
+		err := v.Exec()
+		if err != nil {
+			return err
+		}
+		beego.Info("end reset:", k)
+	}
+	beego.Info("total success reset:", i, " migration")
+	return nil
+}
+
+// first Reset, then Upgrade
+func Refresh() error {
+	err := Reset()
+	if err != nil {
+		return err
+	}
+	return Upgrade(0)
+}
+
+type dataSlice []data
+
+type data struct {
+	created int64
+	name    string
+	m       Migrationer
+}
+
+// Len is part of sort.Interface.
+func (d dataSlice) Len() int {
+	return len(d)
+}
+
+// Swap is part of sort.Interface.
+func (d dataSlice) Swap(i, j int) {
+	d[i], d[j] = d[j], d[i]
+}
+
+// Less is part of sort.Interface. We use count as the value to sort by
+func (d dataSlice) Less(i, j int) bool {
+	return d[i].created < d[j].created
+}
+
+func sortMap(m map[string]Migrationer) dataSlice {
+	s := make(dataSlice, 0, len(m))
+	for k, v := range m {
+		d := data{}
+		d.created = v.GetCreated()
+		d.name = k
+		d.m = v
+		s = append(s, d)
+	}
+	sort.Sort(s)
+	return s
+}