How to install Postgres.app to use PostgreSQL database on Mac

In this tutorial we will learn to install Postgres.app to use PostgreSQL database on Mac.

What is Postgres.app?

Postgres.app is a full-featured PostgreSQL installation packaged as a standard Mac app. -- https://postgresapp.com

Download

Visit postgresapp.com and download the software on your Mac.

Run the installer and move the Postgres.app into the Applications directory.

Default settings

Postgres.app will install on your Mac with the following default settings.

Host	localhost
Port	5432
User	your system user name
Database	same as user
Password	none
Connection URL	postgresql://localhost

Read more...

ES6 - Template Literals (Template strings)

Watch the video tutorial: ES6 Template Literals (Template strings) #02

In this ES6 JavaScript tutorial we will learn about Template Literals (Template strings).

What are Template Literals?

Template literals are string literals that allows us to embed expressions, multi-line strings and string interpolation.

Template literals are enclosed using backtick ` ` instead of single quotes and double quotes.

Let's print the string Hello World using single and double quotes.

console.log('Hello World');
console.log("Hello World");

Now, let's print the same string using template literal.

console.log(`Hello World`);

Read more...

ES6 - var let const

Check out the tutorial video: ES6 var let const #01

In this ES6 JavaScript tutorial we will learn to create variables using var, let and const.

The var keyword

Alright, let's begin by creating a variable using the var keyword.

Let's say we want to create a variable x and assign it a value 10. So, we will write the following line.

var x = 10;

Now, if we want to print the value of x we can console log it by writing the following line.

var x = 10;
console.log(x);

And we get the output 10.

Few important points we must note while using the var keyword to declare variables.

We can redefine the same variable x again and we will not get any error.

So, we can write something like the following.

var x = 10;
console.log(x); // 10
var x = 20;
console.log(x); // 20

Read more...

How to install PostgreSQL on Mac using Homebrew

Click the link: "How to install PostgreSQL on Mac using Homebrew"

In this tutorial we will learn to install PostgreSQL database on Mac using Homebrew.

Prerequisite

It is assumed that you have Homebrew installed on your Mac.

If you don't have Homebrew installed on your Mac then open Terminal and run the following command.

$ /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Alright, time to install PostgreSQL on Mac.

Install PostgreSQL using Homebrew

In Terminal run the following command to install PostgreSQL on Mac using Homebrew.

$ brew install postgres

Start PostgreSQL

To start PostgreSQL run the following command in the Terminal.

$ brew services start postgres

Stop PostgreSQL

To stop PostgreSQL run the following command in the Terminal.

$ brew services stop postgres

Restart PostgreSQL

To restart PostgreSQL run the following command in the Terminal.

$ brew services restart postgres

Read more...

How to change default shell to bash on macOS Catalina

Click the link: "How to change default shell to bash on macOS Catalina"

In this tutorial we will learn to change default shell to bash on macOS Catalina 10.15.

With the release of macOS Catalina 10.15 on 7th October 2019 Apple made zsh as the default shell. You can learn more about it here.

From Apple:

By default, your Mac uses either zsh or bash as the command-line interpreter for the login shell and interactive shell:

• zsh (Z shell) is the default shell for all newly created user accounts, starting with the macOS Catalina beta.
• bash is the default shell in macOS Mojave and earlier.

If you want to make bash as your default command-line interpreter then perform the following steps.

Close Terminal if it is open.

Step 1: Open System Preferences and select Users & Groups

Click on the System Preferences icon or hit Cmd + Spacebar to open Spotlight and type System Preferences and open it.

Now, select Users & Groups.

Step 2: Unlock

At the bottom left you will see the lock. Click it and enter your password to unlock it.

Read more...

How to install Apache, MySQL, PHP on macOS Catalina 10.15

Click the link: "How to install Apache, MySQL, PHP on macOS Catalina 10.15"

In this tutorial we will learn to install Apache, MySQL, PHP on macOS Catalina 10.15.

About macOS Catalina

Apple released macOS Catalina 10.15 on 7th October 2019 and it includes Apache and PHP. So, all we have to do is enable them. Then install MySQL and we are ready for development. So, lets get started.

Note! Support for 32 bit apps is removed in Catalina so, all your 32 bit applications will no longer work. Kindly upgrade your applications.

Apple has also made zsh as the default shell. You can learn more about it here.

To change the default shell check the tutorial How to change default shell to bash on macOS Catalina.

We will be using the pre-installed Apache and PHP and we will download and setup MySQL database.

If you are using macOS Mojave then check out this tutorial How to install Apache, MySQL, PHP on macOS Mojave 10.14

Let's go ahead and configure our LAMP stack development environment on macOS Catalina.

Apache

The new macOS Catalina comes with Apache pre-installed. All we have to do is switch it on.

Open Terminal using macOS Spotlight or go to /Applications/Utilities and open Terminal.

To check the version of Apache installed run the following command in the Terminal.

$ httpd -v

Server version: Apache/2.4.41 (Unix)
Server built:   Aug 29 2019 19:01:57

Note! macOS Catalina comes with Apache 2.4.41

Read more...

MongoDB - Delete Documents

Click the link: "MongoDB - Delete Documents"

In this MongoDB tutorial we will learn to delete documents.

Login to your MongoDB server and insert the following documents.

For this tutorial I will insert the documents in the subscription collection.

> db.subscription.insertMany([
  {
    "firstname": "John",
    "lastname": "Doe",
    "uid": 1,
    "accountstatus": "ACTIVE",
    "plan": "TRIAL15DAYS",
    "modifiedAt": null,
    "createdAt": new Date()
  },
  {
    "firstname": "Jane",
    "lastname": "Doe",
    "uid": 2,
    "accountstatus": "ACTIVE",
    "plan": "PLAN30DAYS",
    "modifiedAt": null,
    "createdAt": new Date()
  },
  {
    "firstname": "Jim",
    "lastname": "Doe",
    "uid": 3,
    "accountstatus": "SUSPENDED",
    "plan": "PLAN60DAYS",
    "modifiedAt": null,
    "createdAt": new Date()
  },
  {
    "firstname": "Alice",
    "lastname": "Doe",
    "uid": 4,
    "accountstatus": "ACTIVE",
    "plan": "PLAN1YEAR",
    "modifiedAt": null,
    "createdAt": new Date()
  }
])

Note! We are using new Date() to set the createdAt to current date time.

Delete one document

We use the deleteOne method to delete one document from a given collection.

In the following example we are deleting document having uid equal to 4.

> db.subscription.deleteOne({ "uid": 4 })

Read more...