Technical Interview Challenge: Using Gorm with MySQL

Recently, I was given a technical interview assignment that pushed me to try new things in my Golang development skills. One of the tasks was to use Gorm to connect to a MySQL database and print the contents of the database. In this blog post, I will share with you the steps I took to achieve this task.

Step 1: Set up the environment
To get started, you need to have the following installed on your machine:

Visual Studio Code
Golang
MySQL
Gorm

Step 2: Create a new Golang project
Open Visual Studio Code and create a new Golang project. You can do this by opening the terminal and running the following command:

mkdir myproject
cd myproject
go mod init myproject

Step 3: Install Gorm and the MySQL driver
Next, you need to install Gorm and the MySQL driver. Run the following commands in the terminal:

go get -u gorm.io/gorm
go get -u gorm.io/driver/mysql
Step 4: Set up the database connection
Now it's time to set up the database connection. Create a new file called database.go in the root of your project and add the following code:

package main

import (
"gorm.io/driver/mysql"
"gorm.io/gorm"
)

func ConnectDB() (*gorm.DB, error) {
dsn := "user:password@tcp(127.0.0.1:3306)/dbname?charset=utf8mb4&parseTime=True&loc=Local"
db, err := gorm.Open(mysql.Open(dsn), &gorm.Config{})
if err != nil {
return nil, err
}
return db, nil
}
Replace user, password, and dbname with your MySQL credentials and database name. This function will return a *gorm.DB object that we can use to interact with the database.

Step 5: Create a model and a migration
To print the contents of the database, we need to create a model and a migration. Create a new file called model.go in the root of your project and add the following code:

package main

import (
"gorm.io/gorm"
)

type User struct {
gorm.Model
Name string
Email string
}

func Migrate() error {
db, err := ConnectDB()
if err != nil {
return err
}
db.AutoMigrate(&User{})
return nil
}
This will create a User model and a migration that will create a users table in the database.

Step 6: Insert some data
Before we can print the contents of the database, we need to insert some data. Create a new file called main.go in the root of your project and add the following code:

package main

import (
"fmt"
)

func main() {
err := Migrate()
if err != nil {
panic(err)
}

db, err := ConnectDB()
if err != nil {
panic(err)
}
defer db.Close()

user := User{Name: "John", Email: "john@example.com"}
db.Create(&user)

var users []User
db.Find(&users)

fmt.Println(users)
}
This code will create a new User object, insert it into the database, fetch all the User objects from the database, and print them to the console.

Step 7: Run the code
Now it's time to run the code. Open the terminal in Visual Studio Code and run