From 7c2ec075a4fb45ca4dd25e7ae7585417d9c99b53 Mon Sep 17 00:00:00 2001
From: Gnanakeethan Balasubramaniam <gnanakeethan@gmail.com>
Date: Thu, 13 Jul 2017 21:03:30 +0530
Subject: [PATCH] Update: fixing some methods and adding documentation

Signed-off-by: Gnanakeethan Balasubramaniam <gnanakeethan@gmail.com>
---
 migration/ddl.go       | 13 ++++++++++++
 migration/doc.go       | 48 ++++++++++++++++++++++++++++++++++++++++++
 migration/migration.go | 16 +++++++++++++-
 3 files changed, 76 insertions(+), 1 deletion(-)
 create mode 100644 migration/doc.go

diff --git a/migration/ddl.go b/migration/ddl.go
index 3b405498..9d4bfc11 100644
--- a/migration/ddl.go
+++ b/migration/ddl.go
@@ -63,6 +63,19 @@ type RenameColumn struct {
 	Column
 }
 
+// CreateTable creates the table on system
+func (m *Migration) CreateTable(tablename, engine, charset string, p ...func()) {
+	m.TableName = tablename
+	m.Engine = engine
+	m.Charset = charset
+	m.ModifyType = "create"
+}
+
+func (m *Migration) AlterTable(tablename string) {
+	m.TableName = tablename
+	m.ModifyType = "alter"
+}
+
 // NewCol creates a new standard column and attaches it to m struct
 func (m *Migration) NewCol(name string) *Column {
 	col := &Column{Name: name}
diff --git a/migration/doc.go b/migration/doc.go
new file mode 100644
index 00000000..51050ed2
--- /dev/null
+++ b/migration/doc.go
@@ -0,0 +1,48 @@
+package migration
+
+/* Package migration enables you to generate migrations back and forth. It generates both migrations.
+
+
+//Creates a table
+m.CreateTable("tablename","InnoDB","utf8");
+
+
+
+//Alter a table
+m.AlterTable("tablename")
+
+
+
+//Standard Column Methods
+* SetDataType
+* SetNullable
+* SetDefault
+* SetUnsigned (use only on integer types unless produces error)
+
+
+//Sets a primary column, multiple calls allowed, standard column methods available
+m.PriCol("id").SetAuto(true).SetNullable(false).SetDataType("INT(10)").SetUnsigned(true)
+
+//UniCol Can be used multiple times, allows standard Column methods. Use same "index" string to add to same index
+m.UniCol("index","column")
+
+//Standard Column Initialisation, can call .Remove() after NewCol("") on alter to remove
+m.NewCol("name").SetDataType("VARCHAR(255) COLLATE utf8_unicode_ci").SetNullable(false)
+m.NewCol("value").SetDataType("DOUBLE(8,2)").SetNullable(false)
+
+//Rename Columns , only use with Alter table, doesn't works with Create, prefix standard column methods with "Old" to
+//create a true reversible migration eg: SetOldDataType("DOUBLE(12,3)")
+m.RenameColumn("from","to")...
+
+
+//Foreign Columns, single columns are only supported, SetOnDelete & SetOnUpdate are available, call appropriately.
+//Supports standard column methods, automatic reverse.
+m.ForeignCol("local_col","foreign_col","foreign_table")
+
+
+
+
+
+
+
+*/
diff --git a/migration/migration.go b/migration/migration.go
index d1387ba0..ef42c986 100644
--- a/migration/migration.go
+++ b/migration/migration.go
@@ -52,6 +52,7 @@ type Migrationer interface {
 	GetCreated() int64
 }
 
+//Migration defines the migrations by either SQL or DDL
 type Migration struct {
 	sqls           []string
 	Created        string
@@ -82,11 +83,24 @@ func init() {
 // Up implement in the Inheritance struct for upgrade
 func (m *Migration) Up() {
 
+	switch m.ModifyType {
+	case "reverse":
+		m.ModifyType = "alter"
+	case "delete":
+		m.ModifyType = "create"
+	}
+	m.sqls = append(m.sqls, m.GetSQL())
 }
 
 // Down implement in the Inheritance struct for down
 func (m *Migration) Down() {
-
+	switch m.ModifyType {
+	case "alter":
+		m.ModifyType = "reverse"
+	case "create":
+		m.ModifyType = "delete"
+	}
+	m.sqls = append(m.sqls, m.GetSQL())
 }
 
 //Migrate adds the SQL to the execution list