Golang Basic Example

Configure the environment

Before you start, make sure you have downloaded and installed the following software:

Confirm that you have completed the installation of the MySQL client.
Completed Create instance and connect to MatrixOne Intelligence through the MySQL client and create a database named test:
```
mysql> create database test;
```
Confirm that you have completed the installation [Golang version 1.18 and above] (https://go.dev/dl/), and you can use the following command line to confirm your Golang version:
```
#To check with Golang installation and its version
go version
```
Confirm that you have installed gorm.io/driver/mysql, and use the go get command to install it. The code is as follows:
```
go get -u gorm.io/driver/mysql
```

You can refer to Golang Connect MatrixOne Intelligence Service to learn how to connect to MatrixOne Intelligence through Golang. This document will guide you how to implement CRUD (create, read, update, delete).

Steps

Connect to MatrixOne Intelligence through the MySQL client. Create a new database called test.
```
mysql> create database test;
```

Create a plain text file named golang_crud_matrixonecloud.go and copy the following code into the file:

package main

import (
    "database/sql"
    "fmt"
    "log"
    _ "github.com/go-sql-driver/mysql"
)

func main() {
   //Open a new connection to MatrixOne Intelligence
    username := "585b49fc_852b_4bd1_b6d1_d64bc1d8xxxx:admin:accountadmin" // modify this
    host := "freetier-01.cn-hangzhou.cluster.matrixonecloud.cn" // modify this
    password := "your_password" // modify this
    port := 6001
    database := "test"
    encodedUsername := url.QueryEscape(username)
    dbConnectionString := encodedUsername + ":" + password + "@tcp(" + host + ":" + strconv.Itoa(port) + ")/" + database
    db, err := sql.Open("mysql", dbConnectionString)
    checkErr(err)

    //Create a table
    _, err2 := db.Exec("CREATE TABLE `userinfo` (`uid` INT(10) NOT NULL AUTO_INCREMENT,`username` VARCHAR(64) NULL DEFAULT NULL,`department` VARCHAR(64) NULL DEFAULT NULL,`created` DATETIME NULL DEFAULT NULL, PRIMARY KEY (`uid`));")
    if err2 != nil {
        log.Fatal(err2)
    }
    fmt.Print("Successfully Created\n")

    // Insert a record
    stmt, err := db.Prepare("INSERT userinfo SET username=?,department=?,created=?")
    checkErr(err)

    res, err := stmt.Exec("Alex", "r&d", "2023-01-01 12:00:00")
    checkErr(err)

    id, err := res.LastInsertId()
    checkErr(err)

    fmt.Println(id)
    //Update a record
    stmt, err = db.Prepare("update userinfo set username=? where uid=?")
    checkErr(err)

    res, err = stmt.Exec("Mark", id)
    checkErr(err)

    affect, err := res.RowsAffected()
    checkErr(err)

    fmt.Println(affect)

    // Query all records
    rows, err := db.Query("SELECT * FROM userinfo")
    checkErr(err)

    for rows.Next() {
        var uid int
        var username string
        var department string
        var created string
        err = rows.Scan(&uid, &username, &department, &created)
        checkErr(err)
        fmt.Println(uid)
        fmt.Println(username)
        fmt.Println(department)
        fmt.Println(created)
    }

    // Delete a record
    stmt, err = db.Prepare("delete from userinfo where uid=?")
    checkErr(err)

    res, err = stmt.Exec(id)
    checkErr(err)

    affect, err = res.RowsAffected()
    checkErr(err)

    fmt.Println(affect)

    db.Close()

}

func checkErr(err error) {
    if err != nil {
        panic(err)
    }
}

Open a new terminal, use the following command line to execute this Golang file.

> go run golang_crud_matrixonecloud.go
Successfully Created
1
1
1
Mark
r&d
2023-01-01
1