[Proposal] Database Migrations;

Summary: The database migrations now can be created using the methods on
the migration struct. it does not break any existing migration features.
it upgrades the migration struct and adds few more struct types so that
the migrations can be efficiently generated for create, alter, reverse,
drop.

Current Features:
* Supports creation of columns
   * `m.NewCol("name").SetDataType("VARCHAR(10)").SetNullable("true")`
   * **NOTE** `SetNullable` & `SetDefault` methods should not be called on
   same column for consistency
* Supports addition of primary keys
   * `m.PriCol("id").SetDataType("INT(10)").SetNullable("true")`
   * **NOTE** `setAuto(true)` can be only called on Primary keys
* Supports addition of unique keys
   * `m.UniCol("unique_index","column_name").SetDataType("VARCHAR(23)").SetNullable("true")`
   * **NOTE** `UniCol` can be called again with the same index name to
   add column to the index
* Supports rename of columns
   * `m.RenameColumn("from_name","to_name")`
   * Allows standard column methods and methods such that, `SetOldDefault` allows
   reversibility of renames

* TODO:
   * ForeignKey

Signed-off-by: Gnanakeethan Balasubramaniam <gnanakeethan@gmail.com>
This commit is contained in:
Gnanakeethan Balasubramaniam 2017-07-06 06:40:28 +05:30
parent 7ec819deed
commit 6b9c3f4824
No known key found for this signature in database
GPG Key ID: 24924006ABA72F31
2 changed files with 333 additions and 30 deletions

View File

@ -12,42 +12,327 @@
// See the License for the specific language governing permissions and
// limitations under the License.
package migration
package m
// Table store the tablename and Column
type Table struct {
TableName string
Columns []*Column
import (
"fmt"
"github.com/astaxie/beego"
)
// Index struct defines the structure of Index Columns
type Index struct {
Name string
}
// Create return the create sql
func (t *Table) Create() string {
return ""
// Foreign struct defines a single foreign relationship
type Foreign struct {
Column *Column
ForeignTable string
ForeignColumn string
}
// Drop return the drop sql
func (t *Table) Drop() string {
return ""
// Unique struct defines a single unique key combination
type Unique struct {
Definition string
Columns []*Column
}
// Column define the columns name type and Default
//Column struct defines a single column of a table
type Column struct {
Name string
Type string
Default interface{}
Name string
Inc string
Null string
Default string
Unsign string
DataType string
remove bool
Modify bool
}
// Create return create sql with the provided tbname and columns
func Create(tbname string, columns ...Column) string {
return ""
// RenameColumn struct allows renaming of columns
type RenameColumn struct {
OldName string
OldNull string
OldDefault string
OldUnsign string
OldDataType string
NewName string
Column
}
// Drop return the drop sql with the provided tbname and columns
func Drop(tbname string, columns ...Column) string {
return ""
// NewCol creates a new standard column and attaches it to m struct
func (m *Migration) NewCol(name string) *Column {
col := &Column{Name: name}
m.AddColumns(col)
return col
}
// TableDDL is still in think
func TableDDL(tbname string, columns ...Column) string {
return ""
//PriCol creates a new primary column and attaches it to m struct
func (m *Migration) PriCol(name string) *Column {
col := &Column{Name: name}
m.AddColumns(col)
m.AddPrimary(col)
return col
}
//UniCol creates / appends columns to specified unique key and attaches it to m struct
func (m *Migration) UniCol(uni, name string) *Column {
col := &Column{Name: name}
m.AddColumns(col)
uniqueOriginal := &Unique{}
for _, unique := range m.Uniques {
if unique.Definition == uni {
unique.AddColumnsToUnique(col)
uniqueOriginal = unique
}
}
if uniqueOriginal.Definition == "" {
unique := &Unique{Definition: uni}
unique.AddColumnsToUnique(col)
m.AddUnique(unique)
}
return col
}
//Remove marks the columns to be removed.
//it allows reverse m to create the column.
func (c *Column) Remove() {
c.remove = true
}
//SetAuto enables auto_increment of column (can be used once)
func (c *Column) SetAuto(inc bool) *Column {
if inc {
c.Inc = "auto_increment"
}
return c
}
//SetNullable sets the column to be null
func (c *Column) SetNullable(null bool) *Column {
if null {
c.Null = "DEFAULT NULL"
} else {
c.Null = "NOT NULL"
}
return c
}
//SetDefault sets the default value, prepend with "DEFAULT "
func (c *Column) SetDefault(def string) *Column {
c.Default = def
return c
}
//SetUnsigned sets the column to be unsigned int
func (c *Column) SetUnsigned(unsign bool) *Column {
if unsign {
c.Unsign = "UNSIGNED"
}
return c
}
//SetDataType sets the dataType of the column
func (c *Column) SetDataType(dataType string) *Column {
c.DataType = dataType
return c
}
//SetOldNullable allows reverting to previous nullable on reverse ms
func (c *RenameColumn) SetOldNullable(null bool) *RenameColumn {
if null {
c.OldNull = "DEFAULT NULL"
} else {
c.OldNull = "NOT NULL"
}
return c
}
//SetOldDefault allows reverting to previous default on reverse ms
func (c *RenameColumn) SetOldDefault(def string) *RenameColumn {
c.OldDefault = def
return c
}
//SetOldUnsigned allows reverting to previous unsgined on reverse ms
func (c *RenameColumn) SetOldUnsigned(unsign bool) *RenameColumn {
if unsign {
c.OldUnsign = "UNSIGNED"
}
return c
}
//SetOldDataType allows reverting to previous datatype on reverse ms
func (c *RenameColumn) SetOldDataType(dataType string) *RenameColumn {
c.OldDataType = dataType
return c
}
//SetPrimary adds the columns to the primary key (can only be used any number of times in only one m)
func (c *Column) SetPrimary(m *Migration) *Column {
m.Primary = append(m.Primary, c)
return c
}
//AddColumnsToUnique adds the columns to Unique Struct
func (unique *Unique) AddColumnsToUnique(columns ...*Column) *Unique {
unique.Columns = append(unique.Columns, column...)
return unique
}
//AddColumns adds columns to m struct
func (m *Migration) AddColumns(columns ...*Column) *Migration {
m.Columns = append(m.Columns, column...)
return m
}
//AddPrimary adds the column to primary in m struct
func (m *Migration) AddPrimary(primary *Column) *Migration {
m.Primary = append(m.Primary, primary)
return m
}
//AddUnique adds the column to unique in m struct
func (m *Migration) AddUnique(unique *Unique) *Migration {
m.Uniques = append(m.Uniques, unique)
return m
}
//AddForeign adds the column to foreign in m struct
func (m *Migration) AddForeign(foreign *Foreign) *Migration {
m.Foreigns = append(m.Foreigns, foreign)
return m
}
//AddIndex adds the column to index in m struct
func (m *Migration) AddIndex(index *Index) *Migration {
m.Indexes = append(m.Indexes, index)
return m
}
//RenameColumn allows renaming of columns
func (m *Migration) RenameColumn(from, to string) *RenameColumn {
rename := &RenameColumn{OldName: from, NewName: to}
m.Renames = append(m.Renames, rename)
return rename
}
//GetSQL returns the generated sql depending on ModifyType
func (m *Migration) GetSQL() (sql string) {
sql = ""
switch m.ModifyType {
case "create":
{
sql += fmt.Sprintf("CREATE TABLE `%s` (", m.TableName)
for index, column := range m.Columns {
sql += fmt.Sprintf("\n `%s` %s %s %s %s %s", column.Name, column.DataType, column.Unsign, column.Null, column.Inc, column.Default)
if len(m.Columns) > index+1 {
sql += ","
}
}
if len(m.Primary) > 0 {
sql += fmt.Sprintf(",\n PRIMARY KEY( ")
}
for index, column := range m.Primary {
sql += fmt.Sprintf(" `%s`", column.Name)
if len(m.Primary) > index+1 {
sql += ","
}
}
if len(m.Primary) > 0 {
sql += fmt.Sprintf(")")
}
for _, unique := range m.Uniques {
sql += fmt.Sprintf(",\n UNIQUE KEY `%s`( ", unique.Definition)
for index, column := range unique.Columns {
sql += fmt.Sprintf(" `%s`", column.Name)
if len(unique.Columns) > index+1 {
sql += ","
}
}
sql += fmt.Sprintf(")")
}
sql += fmt.Sprintf(")ENGINE=%s DEFAULT CHARSET=%s;", m.Engine, m.Charset)
break
}
case "alter":
{
sql += fmt.Sprintf("ALTER TABLE `%s` ", m.TableName)
for index, column := range m.Columns {
if !column.remove {
beego.BeeLogger.Info("col")
sql += fmt.Sprintf("\n ADD `%s` %s %s %s %s %s", column.Name, column.DataType, column.Unsign, column.Null, column.Inc, column.Default)
} else {
sql += fmt.Sprintf("\n DROP COLUMN `%s`", column.Name)
}
if len(m.Columns) > index+1 {
sql += ","
}
}
for index, column := range m.Renames {
sql += fmt.Sprintf(",\n CHANGE COLUMN `%s` `%s` %s %s %s %s %s", column.OldName, column.NewName, column.DataType, column.Unsign, column.Null, column.Inc, column.Default)
if len(m.Renames) > index+1 {
sql += ","
}
}
sql += ";"
break
}
case "reverse":
{
sql += fmt.Sprintf("ALTER TABLE `%s`", m.TableName)
for index, column := range m.Columns {
if column.remove {
sql += fmt.Sprintf("\n ADD `%s` %s %s %s %s %s", column.Name, column.DataType, column.Unsign, column.Null, column.Inc, column.Default)
} else {
sql += fmt.Sprintf("\n DROP COLUMN `%s`", column.Name)
}
if len(m.Columns) > index+1 {
sql += ","
}
}
if len(m.Primary) > 0 {
sql += fmt.Sprintf(",\n DROP PRIMARY KEY")
}
for index, unique := range m.Uniques {
sql += fmt.Sprintf(",\n DROP KEY `%s`", unique.Definition)
if len(m.Uniques) > index+1 {
sql += ","
}
}
for index, column := range m.Renames {
sql += fmt.Sprintf(",\n CHANGE COLUMN `%s` `%s` %s %s %s %s", column.NewName, column.OldName, column.OldDataType, column.OldUnsign, column.OldNull, column.OldDefault)
if len(m.Renames) > index+1 {
sql += ","
}
}
sql += ";"
}
case "delete":
{
sql += fmt.Sprintf("DROP TABLE IF EXISTS `%s`;", m.TableName)
}
}
return
}

View File

@ -52,6 +52,25 @@ type Migrationer interface {
GetCreated() int64
}
type Migration struct {
sqls []string
Created string
TableName string
Engine string
Charset string
ModifyType string
Columns []*Column
Indexes []*Index
Primary []*Column
Uniques []*Unique
Foreigns []*Foreign
Renames []*RenameColumn
RemoveColumns []*Column
RemoveIndexes []*Index
RemoveUniques []*Unique
RemoveForeigns []*Foreign
}
var (
migrationMap map[string]Migrationer
)
@ -60,12 +79,6 @@ func init() {
migrationMap = make(map[string]Migrationer)
}
// Migration the basic type which will implement the basic type
type Migration struct {
sqls []string
Created string
}
// Up implement in the Inheritance struct for upgrade
func (m *Migration) Up() {
@ -76,6 +89,11 @@ func (m *Migration) Down() {
}
func (m *Migration) Migrate(migrationType string) {
m.ModifyType = migrationType
m.sqls = append(m.sqls, m.GetSQL())
}
// SQL add sql want to execute
func (m *Migration) SQL(sql string) {
m.sqls = append(m.sqls, sql)