# mongo

mongo適用于大數(shù)據(jù)量，高并發(fā)，輕量事物型系統(tǒng)

## devops

### 創(chuàng)建管理員賬戶

1. 以非授權(quán)模式啟動(dòng)mongod

```sh

mongod --dbpath /usr/local/var/mongodb --logpath /usr/local/var/log/mongodb/mongo.log --fork

```

2. 創(chuàng)建管理用戶admin

`使用mongosh連接進(jìn)去`

```bash

test> use admin

switched to db admin

admin> db.createUser({

... ? ? user:"admin",

... ? ? pwd:"admin123456",

... ? ? roles:[{role:"userAdminAnyDatabase",db:"admin"}]

... });

{ ok: 1 }

#查看用戶,另外還可以使用db.system.users.find()

admin> show users

[

{

_id: 'admin.admin',

userId: UUID("554560b1-e47b-44d9-8d3a-5f7ae5c933eb"),

user: 'admin',

db: 'admin',

roles: [ { role: 'userAdminAnyDatabase', db: 'admin' } ],

mechanisms: [ 'SCRAM-SHA-1', 'SCRAM-SHA-256' ]

}

]

#退出來(lái)

admin> quit

```

3. 停止數(shù)據(jù)庫(kù)

```sh

killall `pidof mongod`

```

### 創(chuàng)建業(yè)務(wù)賬戶

1. 以授權(quán)模式啟動(dòng)

```bash

```sh

mongod --auth --dbpath /usr/local/var/mongodb --logpath /usr/local/var/log/mongodb/mongo.log --fork

```

```

2. 使用admin登錄

```sh

# 可直接使用mongosh進(jìn)去后使用db.auth('admin','admin123456')再認(rèn)證

mongosh -u admin -p

```

3. 創(chuàng)建業(yè)務(wù)用戶

```sh

test> use biz

biz> db.createUser({user:"webopr",pwd:"123456",roles:[{role:"readWrite",db:"biz"}]})

{ ok: 1 }

```

4. 使用webopr登錄

```sh

test> use biz

switched to db biz

biz> db.auth('webopr','123456')

{ ok: 1 }

biz>

biz> show tables;

# 插入數(shù)據(jù)

biz> db.users.insertOne({uid:0,age:19,name:"EdgeCross",uin:"skyhawk"})

{

acknowledged: true,

insertedId: ObjectId("6438fa7dda4faacf8d683e85")

}

# 查詢剛插入的數(shù)據(jù)

biz> db.users.find();

[

{

_id: ObjectId("6438fa7dda4faacf8d683e85"),

uid: 0,

age: 19,

name: 'EdgeCross',

uin: 'skyhawk'

}

]

```

## 客戶端編碼

### options包

在options包, 可用來(lái)設(shè)置客戶端選項(xiàng)(ClientOptions)。

```go

// 新建客戶端選項(xiàng)

func Client()*ClientOptions

// 連接字符串，DSN

func (c *ClientOptions) GetURI() string

func (c *ClientOptions) ApplyURI(uri string) *ClientOptions

// 參數(shù)設(shè)置... 一些參數(shù)可通過(guò)uri參數(shù)設(shè)置

```

#### 連接字符串

```go

"mongodb://user:password@host:port/db?param1=value1&param2=value2"

```

### mongo包

#### Client

一個(gè)Client對(duì)象是一個(gè)連接池，它是并發(fā)安全的。它可以自動(dòng)地打開和關(guān)閉連接，并維護(hù)一個(gè)空閑的連接池。

連接池的配置選項(xiàng)可通過(guò)options.ClientOptions配置。

```go

// 調(diào)用NewClient創(chuàng)建Client對(duì)象，并調(diào)用Connect方法初始化它。

func Connect(ctx context.Context, opts ...*options.ClientOptions) (*Client, error)

// 創(chuàng)建client對(duì)象

func NewClient(opts ...*options.ClientOptions) (*Client, error)

// 通過(guò)啟動(dòng)后臺(tái)監(jiān)聽協(xié)程來(lái)初始化Client，如果c通過(guò)NewClient函數(shù)創(chuàng)建，該方法必須在client使用之前被調(diào)用。

func (c *Client) Connect(ctx context.Context) error

// 關(guān)閉網(wǎng)絡(luò)連接

func (c *Client) Disconnect(ctx context.Context) error

// Ping 用于驗(yàn)證連接是否建立起來(lái)了（與數(shù)據(jù)庫(kù)的網(wǎng)絡(luò)連接）

func (c *Client) Ping(ctx context.Context, rp *readpref.ReadPref) error

// 根據(jù)給定的選項(xiàng)創(chuàng)建一個(gè)新的會(huì)話，調(diào)用StartSession是線程安全的，但是返回的session不是線程安全的。

func (c *Client) StartSession(opts ...*options.SessionOptions) (Session, error)

// 獲取數(shù)據(jù)庫(kù)句柄

func (c *Client) Database(name string, opts ...*options.DatabaseOptions) *Database

func (c *Client) ListDatabases(ctx context.Context, filter interface{}, opts ...*options.ListDatabasesOptions)

func (c *Client) ListDatabaseNames(ctx context.Context, filter interface{}, opts ...*options.ListDatabasesOptions) ([]string, error)

// session

func WithSession(ctx context.Context, sess Session, fn func(SessionContext) error) error

func (c *Client) UseSession(ctx context.Context, fn func(SessionContext) error) error

func (c *Client) UseSessionWithOptions(ctx context.Context, opts *options.SessionOptions, fn func(SessionContext) error) error

func (c *Client) NumberSessionsInProgress() int

// changestream

func (c *Client) Watch(ctx context.Context, pipeline interface{},

opts ...*options.ChangeStreamOptions) (*ChangeStream, error)

```

#### Database

描述一個(gè)mongoDB數(shù)據(jù)庫(kù)，是線程安全的。

```go

// 獲得一個(gè)集合句柄

func (db *Database) Collection(name string, opts ...*options.CollectionOptions) *Collection

// 在數(shù)據(jù)庫(kù)上執(zhí)行一個(gè)聚合命令

func (db *Database) Aggregate(ctx context.Context, pipeline interface{},

opts ...*options.AggregateOptions) (*Cursor, error)

// 執(zhí)行命令

func (db *Database) RunCommand(ctx context.Context, runCommand interface{}, opts ...*options.RunCmdOptions) *SingleResult

func (db *Database) RunCommandCursor(ctx context.Context, runCommand interface{}, opts ...*options.RunCmdOptions) (*Cursor, error)

// 在數(shù)據(jù)庫(kù)上刪除

func (db *Database) Drop(ctx context.Context) error

// 列出集合

func (db *Database) ListCollectionSpecifications(ctx context.Context, filter interface{},

opts ...*options.ListCollectionsOptions) ([]*CollectionSpecification, error)

func (db *Database) ListCollections(ctx context.Context, filter interface{}, opts ...*options.ListCollectionsOptions) (*Cursor, error)

// 數(shù)據(jù)庫(kù)ChangeStream

func (db *Database) Watch(ctx context.Context, pipeline interface{},

opts ...*options.ChangeStreamOptions) (*ChangeStream, error)

// 顯示的創(chuàng)建集合，如果集合存在，返回錯(cuò)誤

func (db *Database) CreateCollection(ctx context.Context, name string, opts ...*options.CreateCollectionOptions) error

// 創(chuàng)建視圖，視圖是干什么的?

func (db *Database) CreateView(ctx context.Context, viewName, viewOn string, pipeline interface{},

opts ...*options.CreateViewOptions) error

```

#### Collection

描述一個(gè)mongoDB集合，是線程安全的。

```go

// 執(zhí)行一個(gè)批量寫操作

func (coll *Collection) BulkWrite(ctx context.Context, models []WriteModel,

opts ...*options.BulkWriteOptions) (*BulkWriteResult, error)

// 插入

func (coll *Collection) InsertOne(ctx context.Context, document interface{},

opts ...*options.InsertOneOptions) (*InsertOneResult, error)

func (coll *Collection) InsertMany(ctx context.Context, documents []interface{},

opts ...*options.InsertManyOptions) (*InsertManyResult, error)

// 刪除

func (coll *Collection) DeleteOne(ctx context.Context, filter interface{},

opts ...*options.DeleteOptions) (*DeleteResult, error)

func (coll *Collection) DeleteMany(ctx context.Context, filter interface{},

opts ...*options.DeleteOptions) (*DeleteResult, error)

// 更新

func (coll *Collection) UpdateByID(ctx context.Context, id interface{}, update interface{},

opts ...*options.UpdateOptions) (*UpdateResult, error)

func (coll *Collection) UpdateOne(ctx context.Context, filter interface{}, update interface{},

opts ...*options.UpdateOptions) (*UpdateResult, error)

func (coll *Collection) UpdateMany(ctx context.Context, filter interface{}, update interface{},

opts ...*options.UpdateOptions) (*UpdateResult, error)

func (coll *Collection) ReplaceOne(ctx context.Context, filter interface{},

replacement interface{}, opts ...*options.ReplaceOptions) (*UpdateResult, error)

// 執(zhí)行聚合命令

func (coll *Collection) Aggregate(ctx context.Context, pipeline interface{},

opts ...*options.AggregateOptions) (*Cursor, error)

// 統(tǒng)計(jì)文檔數(shù)量

func (coll *Collection) CountDocuments(ctx context.Context, filter interface{},

opts ...*options.CountOptions) (int64, error)

func (coll *Collection) EstimatedDocumentCount(ctx context.Context,

opts ...*options.EstimatedDocumentCountOptions) (int64, error)

func (coll *Collection) Distinct(ctx context.Context, fieldName string, filter interface{},

opts ...*options.DistinctOptions) ([]interface{}, error)

// 查詢

func (coll *Collection) Find(ctx context.Context, filter interface{},

opts ...*options.FindOptions) (cur *Cursor, err error)

func (coll *Collection) FindOne(ctx context.Context, filter interface{},

opts ...*options.FindOneOptions) *SingleResult

func (coll *Collection) FindOneAndDelete(ctx context.Context, filter interface{},

opts ...*options.FindOneAndDeleteOptions) *SingleResult

func (coll *Collection) FindOneAndReplace(ctx context.Context, filter interface{},

replacement interface{}, opts ...*options.FindOneAndReplaceOptions) *SingleResult

func (coll *Collection) FindOneAndUpdate(ctx context.Context, filter interface{},

update interface{}, opts ...*options.FindOneAndUpdateOptions) *SingleResult

// 監(jiān)聽

func (coll *Collection) Watch(ctx context.Context, pipeline interface{},

opts ...*options.ChangeStreamOptions) (*ChangeStream, error)

// 索引視圖

func (coll *Collection) Indexes() IndexView

// 銷毀

func (coll *Collection) Drop(ctx context.Context) error

```

#### ___Cursor___

用于迭代文檔流。通過(guò)Decode或者通過(guò)Current字典訪問(wèn)原始的BSON都可以將一個(gè)數(shù)據(jù)庫(kù)文檔解碼為一個(gè)Go類型。不是線程安全的哦

```go

func (c *Cursor) Next(ctx context.Context) bool

func (c *Cursor) TryNext(ctx context.Context) bool

// 將bson反序列化到val中

func (c *Cursor) Decode(val interface{})

func (c *Cursor) Err() error

func (c *Cursor) Close(ctx context.Context) error

func (c *Cursor) All(ctx context.Context, results interface{}) error

```