Book Image

The Go Workshop

By : Delio D'Anna, Andrew Hayes, Sam Hennessy, Jeremy Leasor, Gobin Sougrakpam, Dániel Szabó
Book Image

The Go Workshop

By: Delio D'Anna, Andrew Hayes, Sam Hennessy, Jeremy Leasor, Gobin Sougrakpam, Dániel Szabó

Overview of this book

The Go Workshop will take the pain out of learning the Go programming language (also known as Golang). It is designed to teach you to be productive in building real-world software. Presented in an engaging, hands-on way, this book focuses on the features of Go that are used by professionals in their everyday work. Each concept is broken down, clearly explained, and followed up with activities to test your knowledge and build your practical skills. Your first steps will involve mastering Go syntax, working with variables and operators, and using core and complex types to hold data. Moving ahead, you will build your understanding of programming logic and implement Go algorithms to construct useful functions. As you progress, you'll discover how to handle errors, debug code to troubleshoot your applications, and implement polymorphism using interfaces. The later chapters will then teach you how to manage files, connect to a database, work with HTTP servers and REST APIs, and make use of concurrent programming. Throughout this Workshop, you'll work on a series of mini projects, including a shopping cart, a loan calculator, a working hours tracker, a web page counter, a code checker, and a user authentication system. By the end of this book, you'll have the knowledge and confidence to tackle your own ambitious projects with Go.
Table of Contents (21 chapters)
Free Chapter
1. Variables and Operators
2. Logic and Loops

Updating Existing Data

When you are updating a row or multiple rows with Go, you are in trouble. The sql package does not provide any function called Update(); however, there is the Exec() function, which serves as a universal executor for your queries. You can execute SELECT, UPDATE, DELETE, or whatever you need to execute with this function. This topic will show you how you can do it safely.

We would like to start our script in the usual way. It can be found in the examples folder and is called DBUpdate.go:

package main
import "fmt"
import "database/sql"
import _ ""

Then the magic comes. The idea is to update the name column's value for a specific id variable that we give as an argument. So, the main() function looks like this:

func main(){
db, err := sql.Open("postgres", "user=postgres password=Start!123 host= port=5432 dbname=postgres sslmode=disable")
if err != nil {