A command so important, it deserves its own page:

1git reset --soft HEAD~1

The previous command undoes the last commit to git. I think this is one of those commands that I have typed many times during the last year. It’s very important to know …

Should I use a map or a list? A simple rule:

• If you need to update or remove an item, lists only allow you to do it by index. While maps let you do it by key.

Their simplified representation goes like this:

1{
2  "someMap": {
3 …

This article discusses different approaches for testing classes, services, and PlayFramework controllers using scalatest.

Setting up the project dependencies

First step is to add to build.sbt the next dependency:

1"org.scalatest" %% …

Using case object

Unlike other languages, Scala does not have a keyword for enumerations. One way to implement them is by using case objects. For example:

1sealed trait OperatingSystem extends Product with Serializable
2
3object OperatingSystem {
4 …

On this article we are going to install a rancher server on Ubuntu. Let’s start by getting the rancher image from docker hub:

1sudo docker run -d --restart=always -p 8080:8080 --name=rancher-server rancher/server

Go to http://ip-address:8080 …

This article shows a list of basic commands on MySQL and their corresponding versions for PostgreSQL.

Connecting to a database

MySQL

1$ mysql -u root -p

Postgres

1$ psql -h <host> -U <username> <database-name>

Try the following if …

This article describes some ideas on getting a successful software development process.

A successful project:

• Depends on the expertise of the team. Don’t try to push many new technologies into a project. It will be difficult for the team to …

MySQL allows you to store credentials in a file called ~/.my.cnf. The contents can look like this:

[mysqldump]
user=myuser
password=mypassword

We have to modify the file permissions and give read/write permissions to the owner only:

1chmod 600 …

The following examples use random generated numbers initialized with a static seed. Never do it like this.

Run the following examples multiple times to understand why it is important to have a good seed.

PHP version:

1#!/usr/bin/php
2
3<?php
4 …

How to install MySQL server in Ubuntu

It’s pretty simple:

1sudo apt-get install mysql-server

How to connect to MySQL using Java

This is a useful and simple snippet:

 1import java.sql.Connection;
 2import java.sql.DriverManager;
 3public class Test { …