Connecting MySQL

Just like Redis gofr also supports connection to SQL(mysql and postgres) databases based on configuration variables.

Setup

Users can run MySQL and create a database locally using the following docker command:

docker run --name gofr-mysql -e MYSQL_ROOT_PASSWORD=root123 -e MYSQL_DATABASE=test_db -p 3306:3306 -d mysql:8.0.30

Access test_db database and create table customer with columns id and name

docker exec -it gofr-mysql mysql -uroot -proot123 test_db -e "CREATE TABLE customers (id INT AUTO_INCREMENT PRIMARY KEY, name VARCHAR(255) NOT NULL);"

Now the database with table is ready, we can connect our GoFr server to MySQL

Configuration & Usage

After adding MySQL configs .env will be updated to the following.

# configs/.env
APP_NAME=test-service
HTTP_PORT=9000

REDIS_HOST=localhost
REDIS_PORT=6379

DB_HOST=localhost
DB_USER=root
DB_PASSWORD=root123
DB_NAME=test_db
DB_PORT=3306
DB_DIALECT=mysql

Now in the following example, we'll store customer data using POST /customer and then use GET /customer to retrieve the same. We will be storing the customer data with id and name.

After adding code to add and retrieve data from MySQL datastore, main.go will be updated to the following.

package main

import (
	"errors"

	"github.com/redis/go-redis/v9"
	
	"gofr.dev/pkg/gofr"
)

type Customer struct {
	ID   int    `json:"id"`
	Name string `json:"name"`
}

func main() {
	// initialise gofr object
	app := gofr.New()

	app.GET("/redis", func(ctx *gofr.Context) (interface{}, error) {
		// Get the value using the Redis instance

		val, err := ctx.Redis.Get(ctx.Context, "test").Result()
		if err != nil && !errors.Is(err, redis.Nil) {
			// If the key is not found, we are not considering this an error and returning ""
			return nil, err
		}

		return val, nil
	})

	app.POST("/customer/{name}", func(ctx *gofr.Context) (interface{}, error) {
		name := ctx.PathParam("name")

		// Inserting a customer row in database using SQL
		_, err := ctx.SQL.ExecContext(ctx, "INSERT INTO customers (name) VALUES (?)", name)

		return nil, err
	})

	app.GET("/customer", func(ctx *gofr.Context) (interface{}, error) {
		var customers []Customer

		// Getting the customer from the database using SQL
		rows, err := ctx.SQL.QueryContext(ctx, "SELECT * FROM customers")
		if err != nil {
			return nil, err
		}

		for rows.Next() {
			var customer Customer
			if err := rows.Scan(&customer.ID, &customer.Name); err != nil {
				return nil, err
			}

			customers = append(customers, customer)
		}

		// return the customer
		return customers, nil
	})
	
	app.Run()
}

To update the database with the customer data access use through this curl command through terminal

# here abc and xyz after /customer are the path parameters
curl --location --request POST 'http://localhost:9000/customer/abc'

curl --location --request POST 'http://localhost:9000/customer/xyz'

Now when we access http://localhost:9000/customer we should see the following output

{
  "data": [
    {
      "id": 1,
      "name": "abc"
    },
    {
      "id": 2,
      "name": "xyz"
    }
  ]
}