Golang Basic Learning-mongodb Use

1. System environment

• Golang:go version go1.10.3 Darwin/amd64
• Os:macos
• mongobd:version:3.4.4

2.Golang using MongoDB

Use: Gopkg.in/mgo.v2

  获取包：go get gopkg.in/mgo.v2  引入：import "gopkg.in/mgo.v2"

About MgO

3. Simply use MongoDB

3.1 Data design

3.1.1 Database design:

Database name: mydb_tutorial
Collection Name: t_student

Data collection: T_student field description

Field	type	Description
Name	String	Name
Age	Int	Age
Sid	String	School Number
Status	Int	Status: 1 Normal, 9, delete

3.1.2 Structure Design:

type Student struct {    Name   string  `bson: "name"`    Age    int     `bson: "age"`    Sid    string  `bson: "sid"`    Status int     `bson: "status"`}type Per struct {    Per   []Student}

About MgO

func Dial(url string) (*Session, error)官方简介：Dial establishes a new session to the cluster identified by the given seed server(s).

3.2 Inserting data

    mongo, err := mgo.Dial("127.0.0.1") // 建立连接     defer mongo.Close()    if err != nil {        return false    }    client := mongo.DB("mydb_tutorial").C("t_student")  //选择数据库和集合    //创建数据    data := Student{        Name:   "seeta",        Age:    18,        Sid:    "s20180907",        Status: 1,    }    //插入数据    cErr := client.Insert(&data)    if cErr != nil {        return false    }    return true

The implementation of the program, MongoDB will appear a record:

3.3 Finding data

on the basis of inserting data in 3.2, we insert another piece of data:

data := Student{        Name:   "seeta1",        Age:    18,        Sid:    "s20180908",        Status: 1,    }

3.3.1 FindOne

mongo, err := mgo.Dial("192.168.0.91")    defer mongo.Close()    if err != nil {        return false    }    client := mongo.DB("mydb_tutorial").C("t_student")    user := Student{}//查找sid为 s20180907    cErr := client.Find(bson.M{"sid": "s20180907"}).One(&user)    if cErr != nil {        return false    }    fmt.Println(user)    return true

When you execute the program, the results you find are printed:

{Seeta s20180907 1}

3.3.2 FindAll

Find data with status 1

mongo, err := mgo.Dial("192.168.0.91")    defer mongo.Close()    if err != nil {        return false    }    client := mongo.DB("mydb_tutorial").C("t_student")    //每次最多输出15条数据    iter := client.Find(bson.M{"status": 1}).Sort("_id").Skip(1).Limit(15).Iter()    var stu Student    var users Per    for iter.Next(&stu) {        users.Per = append(users.Per, stu)    }    if err := iter.Close(); err != nil {        return false    }    fmt.Println(users)    return true

When you execute the program, the results you find are printed:

{[{seeta1 s20180908 1} {Seeta s20180907 1}]}

3.4 Updating data

Before updating the data:

    mongo, err := mgo.Dial("192.168.0.91")    defer mongo.Close()    if err != nil {        return false    }    client := mongo.DB("mydb_tutorial").C("t_student")    //只更新一条    cErr := client.Update(bson.M{"status": 1}, bson.M{"$set": bson.M{"age": 20}})        if cErr != nil {        return false    }    return true}

After executing the command:

Age of only one piece of data updated

If we want to update the age of all students with status 1 to 20.

with the client. UpdateAll Replace the client. Update is available.

3.5 Deleting data

Delete data: SID is s20180907

    mongo, err := mgo.Dial("192.168.0.91")    defer mongo.Close()    if err != nil {        return false    }    client := mongo.DB("mydb_tutorial").C("t_student")    //只更新一条    cErr := client.Remove(bson.M{"sid": "s20180907"})    if cErr != nil {        return false    }    return true

If the database is designed, there are two SIDs for s20180907 and only one record is deleted.
If you delete all: With client. RemoveAll Replace the client. Remove

4. Other

Wrote a gin and MgO combined data Query service demo, details can be clicked linked to GitHub view