Golang : Update database with GORM example

A simple tutorial on how to use GORM(Golang Object Relational Map) to connect to a MySQL/MariaDB database and UPDATE data.

Here you go!

 package main

 import (
 "fmt"
 _ "github.com/go-sql-driver/mysql"
 "github.com/jinzhu/gorm"
 "time"
 )

 // Activities table SQL :
 // id bigint(20)  AUTO_INCREMENT
 // username varchar(50)
 // created_on  timestamp
 // action char(1)
 // description varchar(300)
 // visibility  char(1)

 // NOTE : In the struct, CreatedOn will be translated into created_on in sql level
 type Activities struct {
 Id int `sql:"AUTO_INCREMENT"`
 Username string `sql:"varchar(50);unique"`
 CreatedOn time.Time `sql:"timestamp"`
 Action string `sql:"type:char(1)"`
 Description string `sql:"type:varchar(300)"`
 Visibility  string `sql:"type:char(1)"`
 }

 func main() {

 dbConn, err := gorm.Open("mysql", "username:password@tcp(x0.xx0.xxx.xxx:3306)/db_name?charset=utf8&parseTime=true")

 if err != nil {
 fmt.Println(err)
 }

 dbConn.DB()
 dbConn.DB().Ping()
 dbConn.DB().SetMaxIdleConns(10)
 dbConn.DB().SetMaxOpenConns(100)

 activity := Activities{
 Username: "testuser",
 CreatedOn: time.Now().UTC(),
 Description: "Testing",
 Visibility:  "S",
 }

 dbConn.Create(&activity)

 // use a clean Activities struct for update purpose
 act := Activities{}

 // Get the last record
 dbConn.Last(&act)

 fmt.Println("Before update: ", act)

 fmt.Println("Created on : ", act.CreatedOn)

 currentId := act.Id

 fmt.Println("Current ID : ", currentId)

 // update the last activity struct
 act.Username = "test test test"
 act.Description = "This is a test test test description"
 act.Visibility = "A"

 //dbConn.Save(&act) // update current id

 // best practice is to include the id for the update statement
 dbConn.Where("id = ?", currentId).Save(&act)

 // Get the last record - again
 dbConn.Last(&act)

 fmt.Println("After update : ", act)

 }

Sample output :

Before update: {27570 testuser 2015-07-29 03:29:44 +0000 UTC Testing S}

Created on : 2015-07-29 03:29:44 +0000 UTC

Current ID : 27570

After update : {27570 test test test 2015-07-29 03:29:44 +0000 UTC This is a test test test description A}

References :

https://github.com/jinzhu/gorm

https://www.socketloop.com/tutorials/golang-gorm-read-from-database-example