mongodb + Go
 2018-04-25

Mongodb

安装

略

操作

  1. 启动后台服务程序 
    mongod  # 如果是默认的数据路径需要root权限， 可以修改数据存储位置。
  2. 进入命令行 ```

    mongo

    show databases # 列出数据库 use {database_name} # 切换db指针到某个数据库 show collections # 展示所有的collections (tables) db.{collection_name}.find() # 列出所有元素 .pretty() # 以格式化的json形式展示结果

db.{c_name}.insert({json}) # 插入 db.{c_name}.remove({‘title’: ‘what’}) # 删除指定条件元素 ```

Go 操作Mongodb + 抽象工厂模式设计

import "gopkg.in/mgo.v2"

/** Databaser is An abstract factory interface, if you want to add a new database backend, you must implement all function*/
type Databaser interface {
	iUser
}

func GetDatabaseConncect(db string) (Databaser) {
	if db == "mongodb" { return newMongodb()}
	panic("db is not the validate database backend.")
	return nil
}

// anonymous member, we can directly point the final function, such as AddUser.
type Mongodb struct{
	MongodbUser
}

/** The models definition and corresponding interface. */
type User struct {
	// user'name or oauth2 website username
	Username	string
	// oauth2 authenticated website
	Source 		string
}

type iUser interface {
	AddUser(user User) (error)
	DeleteUser(user User) (error)
	SelectUser(pairs map[string]string) ([]User, error)
}

type MongodbUser struct {
	database 	string
	collection  string	`collection name`
}

// Mongodb's construction, also construct it's interface implementation struct, i.e. subclass.
func newMongodb() (*Mongodb){
	var mdb = new(Mongodb)
	// construct All databases name and collections name, need to be explicit.
	mdb.MongodbUser.database = "Mongodb";
	mdb.MongodbUser.collection = "Users";	// table name.
	return mdb
}

func (self MongodbUser) AddUser(user User) (error) {
	session, err := mgo.Dial(MONGO_DB_SEVER)
	if err != nil {
		return err
	}
	defer session.Close()
	session.SetSafe(&mgo.Safe{})

	c := session.DB(self.database).C(self.collection)
	err = c.Insert(&user)		// It can insert not only one Object, it acquires "...&interface"
	if err != nil {
		return err
	}
	return nil;
}

func (self MongodbUser) DeleteUser(user User) (error) {
	return nil;
}

func (self MongodbUser) SelectUser(pairs map[string]string) ([]User, error) {
	return nil, nil;
}

抽象工厂模式