A Simple example of how to use interfaces in go

interfaces.go

package main

import "fmt"

type DataSource interface {
	Connect() error
	Disconnect() error
}

type Postgres struct {
	name string
}

func (p *Postgres) Connect() error {
	fmt.Println("Connected to Postgres")
	return nil
}

func (p *Postgres) Disconnect() error {
	fmt.Println("Disconnected from Postgres")
	return nil
}

type MySQL struct {
	name string
}

func (m *MySQL) Connect() error {
	fmt.Println("Connected to MySQL")
	return nil
}

func (m *MySQL) Disconnect() error {
	fmt.Println("Disconnected from MySQL")
	return nil
}

func main() {

	NewDao(&Postgres{
		name: "Postgres",
	})

	NewDao(&MySQL{
		name: "MySQL",
	})
	
}

func NewDao(p DataSource) {
	fmt.Println("Creating new DAO with name: ", p)
}