How to use Golang with MySQL?

Golang is a widely used language for building scalable and reliable web applications.

When it comes to Storing data (relational), MySQL is one of the old and preferred ways as a database for many organisations.

This blog post will look at how to use Golang with MySQL by establishing the connection and printing the version using a simple query.

In upcoming blog posts, we will see advanced operations.

Prerequisites

To follow along with this tutorial, you should have the following installed on your machine:

Golang
MySQL

Installing the MySQL driver

The first step is to install the MySQL driver for Golang. This driver lets us connect to a MySQL database from our Golang application. To install the MySQL driver, open a terminal and run the following command:

go get -u github.com/go-sql-driver/mysql

Here’s the sample code. Take a minute and go through the code. Afterwards, we will discuss one line at a time.

package main

import (
    "database/sql"
    "fmt"
    "log"

    _ "github.com/go-sql-driver/mysql"
)

func main() {
    db, err := sql.Open("mysql", "username:password@tcp(127.0.0.1:3306)/testdb")
    defer db.Close()

    if err != nil {
        log.Fatal(err)
    }

    pingErr := db.Ping()
    if pingErr != nil {
        log.Fatal(pingErr)
    }

    fmt.Println("Connected!")

    var version string
    scanEerr := db.QueryRow("SELECT VERSION()").Scan(&version)

    if scanErr != nil {
        log.Fatal(scanErr)
    }

    fmt.Println(version)
}

Let’s understand one by one

we need to connect to the MySQL database from our Golang application. To do this, we will use the database/sql package in the Go standard library. This package provides a common interface for working with different SQL databases.
- underscore alias _ will import the package but will use it explicitly. It will be indirectly used for initialising the database drivers.

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

Now, we need to open a connection to the MySQL database. We can do this by calling the sql.Open() function and passing in the MySQL driver name and a connection string.
- The first field is the name of the driver (mysql in this case)
- The second field is the DSN (Data source name)format which consists of username, password, protocol, address and name of the database, etc.

    db, err := sql.Open("mysql", "username:password@tcp(127.0.0.1:3306)/testdb")

Ensure that the connection is properly closed when the application exits with the help of the following defer statement.

defer db.Close()

Let’s ping the database to verify that our program can connect to the database. If this function doesn’t return any error (nil), then we can establish the connection successfully.

pingErr := db.Ping()

The QueryRow the function executes a query that will return at most one row. The Scan function will store output from the matched row into the version variable.

    var version string
    scanErr := db.QueryRow("SELECT VERSION()").Scan(&version)

The output of the program will be as shown below:

$ go run main.go
Connected!
5.7.38

Thank you for reading. If you have any questions, do let me know in the comments.

I hope you learned something new from this blog post. Click here to learn about me and how you can support my work, Thank you.

Prerequisites#

Let’s understand one by one#

Prerequisites

Let’s understand one by one