Qmgo

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Qmgo is a Go driver for MongoDB . It is based on MongoDB official driver, but easier to use like mgo (such as the chain call).

Qmgo allows users to use the new features of MongoDB in a more elegant way.
Qmgo is the first choice for migrating from mgo to the new MongoDB driver with minimal code changes.

Requirements

-Go 1.10 and above.

-MongoDB 2.6 and above.

Features

CRUD to documents, with all official supported options
Sort、limit、count、select、distinct
Transactions
Hooks
Automatically default and custom fields
Predefine operator keys
Aggregate、indexes operation、cursor
Validation tags
Plugin

Installation

Use go mod to automatically install dependencies by import github.com/qiniu/qmgo

Use go get github.com/qiniu/qmgo

Usage

Start

import and create a new connection

import (
    "context"
  
    "github.com/qiniu/qmgo"
)

ctx := context.Background()
client, err := qmgo.NewClient(ctx, &qmgo.Config{Uri: "mongodb://localhost:27017"})
db := client.Database("class")
coll := db.Collection("user")

If your connection points to a fixed database and collection, recommend using the following way to initialize the connection. All operations can be based on cli:

cli, err := qmgo.Open(ctx, &qmgo.Config{Uri: "mongodb://localhost:27017", Database: "class", Coll: "user"})

The following examples will be based on cli, if you use the first way for initialization, replace cli with client、db or coll

Make sure to defer a call to Disconnect after instantiating your client:

defer func() {
if err = cli.Close(ctx); err != nil {
        panic(err)
    }
}()

Create index

Before doing the operation, we first initialize some data:

type UserInfo struct {
    Name   string `bson:"name"`
    Age    uint16 `bson:"age"`
    Weight uint32 `bson:"weight"`
}

var userInfo = UserInfo{
    Name: "xm",
    Age: 7,
    Weight: 40,
}

Create index

cli.CreateOneIndex(context.Background(), options.IndexModel{Key: []string{"name"}, Unique: true})
cli.CreateIndexes(context.Background(), []options.IndexModel{{Key: []string{"id2", "id3"}}})

Insert a document

// insert one document
result, err := cli.InsertOne(ctx, userInfo)

Find a document

// find one document
  one := UserInfo{}
  err = cli.Find(ctx, bson.M{"name": userInfo.Name}).One(&one)

Delete documents
```
err = cli.Remove(ctx, bson.M{"age": 7})
```

Insert multiple data

// multiple insert
var userInfos = []UserInfo{
    UserInfo{Name: "a1", Age: 6, Weight: 20},
    UserInfo{Name: "b2", Age: 6, Weight: 25},
    UserInfo{Name: "c3", Age: 6, Weight: 30},
    UserInfo{Name: "d4", Age: 6, Weight: 35},
    UserInfo{Name: "a1", Age: 7, Weight: 40},
    UserInfo{Name: "a1", Age: 8, Weight: 45},
}
result, err = cli.Collection.InsertMany(ctx, userInfos)

Search all, sort and limit

// find all, sort and limit
batch := []UserInfo{}
cli.Find(ctx, bson.M{"age": 6}).Sort("weight").Limit(7).All(&batch)

Count

count, err := cli.Find(ctx, bson.M{"age": 6}).Count()

Update

// UpdateOne one
err := cli.UpdateOne(ctx, bson.M{"name": "d4"}, bson.M{"$set": bson.M{"age": 7}})

// UpdateAll
result, err := cli.UpdateAll(ctx, bson.M{"age": 6}, bson.M{"$set": bson.M{"age": 10}})

Select

err := cli.Find(ctx, bson.M{"age": 10}).Select(bson.M{"age": 1}).One(&one)

Aggregate

matchStage := bson.D{{"$match", []bson.E{{"weight", bson.D{{"$gt", 30}}}}}}
groupStage := bson.D{{"$group", bson.D{{"_id", "$name"}, {"total", bson.D{{"$sum", "$age"}}}}}}
var showsWithInfo []bson.M
err = cli.Aggregate(context.Background(), Pipeline{matchStage, groupStage}).All(&showsWithInfo)

Support All mongoDB Options when create connection

poolMonitor := &event.PoolMonitor{
    Event: func(evt *event.PoolEvent) {
        switch evt.Type {
        case event.GetSucceeded:
            fmt.Println("GetSucceeded")
        case event.ConnectionReturned:
            fmt.Println("ConnectionReturned")
        }
    },
}
opt := options.Client().SetPoolMonitor(poolMonitor)  // more options use the chain options.
cli, err := Open(ctx, &Config{Uri: URI, Database: DATABASE, Coll: COLL}, opt)

Transactions

The super simple and powerful transaction, with features like timeout、retry:

callback := func(sessCtx context.Context) (interface{}, error) {
    // Important: make sure the sessCtx used in every operation in the whole transaction
    if _, err := cli.InsertOne(sessCtx, bson.D{{"abc", int32(1)}}); err != nil {
        return nil, err
    }
    if _, err := cli.InsertOne(sessCtx, bson.D{{"xyz", int32(999)}}); err != nil {
        return nil, err
    }
    return nil, nil
}
result, err = cli.DoTransaction(ctx, callback)

More about transaction

Predefine operator keys

// aggregate
matchStage := bson.D{{operator.Match, []bson.E{{"weight", bson.D{{operator.Gt, 30}}}}}}
groupStage := bson.D{{operator.Group, bson.D{{"_id", "$name"}, {"total", bson.D{{operator.Sum, "$age"}}}}}}
var showsWithInfo []bson.M
err = cli.Aggregate(context.Background(), Pipeline{matchStage, groupStage}).All(&showsWithInfo)

Hooks

Qmgo flexible hooks:

type User struct {
    Name         string    `bson:"name"`
    Age          int       `bson:"age"`
}
func (u *User) BeforeInsert() error {
    fmt.Println("before insert called")
    return nil
}
func (u *User) AfterInsert() error {
    fmt.Println("after insert called")
    return nil
}

u := &User{Name: "Alice", Age: 7}
_, err := cli.InsertOne(context.Background(), u)

More about hooks

Automatically fields

Qmgo support two ways to make specific fields automatically update in specific API

Default fields

Inject field.DefaultField in document struct, Qmgo will update createAt、updateAt and _id in update and insert operation.

type User struct {
  field.DefaultField `bson:",inline"`

  Name string `bson:"name"`
  Age  int    `bson:"age"`
}

u := &User{Name: "Lucas", Age: 7}
_, err := cli.InsertOne(context.Background(), u)
// Fields with tag createAt、updateAt and _id will be generated automatically

Custom fields

Define the custom fields, Qmgo will update them in update and insert operation.

type User struct {
    Name string `bson:"name"`
    Age  int    `bson:"age"`

    MyId         string    `bson:"myId"`
    CreateTimeAt time.Time `bson:"createTimeAt"`
    UpdateTimeAt int64     `bson:"updateTimeAt"`
}
// Define the custom fields
func (u *User) CustomFields() field.CustomFieldsBuilder {
    return field.NewCustom().SetCreateAt("CreateTimeAt").SetUpdateAt("UpdateTimeAt").SetId("MyId")
}

u := &User{Name: "Lucas", Age: 7}
_, err := cli.InsertOne(context.Background(), u)
// CreateTimeAt、UpdateTimeAt and MyId will be generated automatically 

// suppose Id and ui is ready
err = cli.ReplaceOne(context.Background(), bson.M{"_id": Id}, &ui)
// UpdateTimeAt will update

Check examples here

More about automatically fields

Validation tags

Qmgo Validation tags is Based on go-playground/validator.

So Qmgo support all validations on structs in go-playground/validator, such as:

type User struct {
    FirstName string            `bson:"fname"`
    LastName  string            `bson:"lname"`
    Age       uint8             `bson:"age" validate:"gte=0,lte=130" `    // Age must in [0,130]
    Email     string            `bson:"e-mail" validate:"required,email"` //  Email can't be empty string, and must has email format
    CreateAt  time.Time         `bson:"createAt" validate:"lte"`          // CreateAt must lte than current time
    Relations map[string]string `bson:"relations" validate:"max=2"`       // Relations can't has more than 2 elements
}

Qmgo tags only supported in following API： InsertOne、InsertyMany、Upsert、UpsertId、ReplaceOne

Plugin
- Implement following method:
```
func Do(doc interface{}, opType operator.OpType, opts ...interface{}) error{
  // do anything
}
```
- Call Register() in package middleware, register the method Do
  
  Qmgo will call Do before and after the operation
```
middleware.Register(Do)
```
Example

The hook、automatically fields and validation tags in Qmgo run on plugin.

`Qmgo` vs `go.mongodb.org/mongo-driver`

Below we give an example of multi-file search、sort and limit to illustrate the similarities between qmgo and mgo and the improvement compare to go.mongodb.org/mongo-driver. How do we do ingo.mongodb.org/mongo-driver:

// go.mongodb.org/mongo-driver
// find all, sort and limit
findOptions := options.Find()
findOptions.SetLimit(7) // set limit
var sorts D
sorts = append(sorts, E{Key: "weight", Value: 1})
findOptions.SetSort(sorts) // set sort

batch := []UserInfo{}
cur, err := coll.Find(ctx, bson.M{"age": 6}, findOptions)
cur.All(ctx, &batch)

How do we do in Qmgo and mgo:

// qmgo
// find all, sort and limit
batch := []UserInfo{}
cli.Find(ctx, bson.M{"age": 6}).Sort("weight").Limit(7).All(&batch)

// mgo
// find all, sort and limit
coll.Find(bson.M{"age": 6}).Sort("weight").Limit(7).All(&batch)

`Qmgo` vs `mgo`

Differences between qmgo and mgo

Contributing

The Qmgo project welcomes all contributors. We appreciate your help!

Communication:

Join gitter room
Join qmgo discussions

nomos/qmgo