The C# Workshop. E-Book

Jason Hales

• Herausgeber: Packt Publishing
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 774

Veröffentlichungsjahr: 2022

Beschreibung

C# is a powerful, versatile language that can unlock a variety of career paths. But, as with any programming language, learning C# can be a challenging process. With a wide range of different resources available, it’s difficult to know where to start.
That's where The C# Workshop comes in. Written and reviewed by industry experts, it provides a fast-paced, supportive learning experience that will quickly get you writing C# code and building applications. Unlike other software development books that focus on dry, technical explanations of the underlying theory, this Workshop cuts through the noise and uses engaging examples to help you understand how each concept is applied in the real world.
As you work through the book, you'll tackle realistic exercises that simulate the type of problems that software developers work on every day. These mini-projects include building a random-number guessing game, using the publisher-subscriber model to design a web file downloader, creating a to-do list using Razor Pages, generating images from the Fibonacci sequence using async/await tasks, and developing a temperature unit conversion app which you will then deploy to a production server.
By the end of this book, you'll have the knowledge, skills, and confidence to advance your career and tackle your own ambitious projects with C#.

Leseprobe

The

C#

Workshop

Kickstart your career as a software developer with C#

Jason Hales, Almantas Karpavicius, and Mateus Viegas

The C# Workshop

Copyright © 2022 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the authors nor Packt Publishing and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

Authors: Jason Hales, Almantas Karpavicius, and Mateus Viegas

Reviewers: Omprakash Pandey and Dara Oladapo

Development Editor: M Keerthi Nair

Acquisitions Editors: Royluis Rodrigues, Kunal Sawant, and Anindya Sil

Production Editor: Shantanu Zagade

Editorial Board: Vijin Boricha, Megan Carlisle, Ketan Giri, Heather Gopsill, Akin Babu Joseph, Bridget Kenningham, Manasa Kumar, Alex Mazonowicz, Monesh Mirpuri, Aaron Nash, Abhishek Rane, Brendan Rodrigues, Ankita Thakur, Nitesh Thakur, and Jonathan Wray

First published: September 2022

Production reference: 1260922

ISBN: 978-1-80056-649-1

Published by Packt Publishing Ltd.

Livery Place, 35 Livery Street

Birmingham B3 2PB, UK

Table of Contents

Preface

1. Hello C#

Introduction

Running and Developing C# with the .NET CLI

Creating Programs with the CLI and VS Code

Basic Anatomy of a C# Program

Exercise 1.01: Creating a Console App that Says "Hello World"

Top-Level Statements

Declaring Variables

Declaring Variables Explicitly

Declaring Variables Implicitly

Explicit versus Implicit Declaration

Exercise 1.02: Assigning Variables to User Inputs

Data Types

Strings

Exercise 1.03: Checking String Immutability

Comparing Strings

Numeric Types

Exercise 1.04: Using the Basic Arithmetic Operators

Classes

Dates

Exercise 1.05: Using Date Arithmetic

Formatting Dates

Logical Operators and Boolean Expressions

Using if-else Statements

Exercise 1.06: Branching with if-else

The Ternary Operator

Reference and Value Types

Exercise 1.07: Grasping Value and Reference Equality

Default Value Types

Enhancing Decision Making with the switch Statement

Exercise 1.08: Using switch to Order Food

Iteration Statements

while

Exercise 1.09: Checking Whether a Number is Prime with a while Loop

Jump Statements

do-while

Arrays

for Loops

Exercise 1.10: Ordering an Array Using Bubble Sort

foreach Statements

File Handling

FileAccess

FileMode

Exercise 1.11: Reading Content from Text Files

Disposable Objects

Exercise 1.12: Writing to a Text File

Exceptions

Exercise 1.13: Handling Invalid User Inputs with try/catch

Activity 1.01: Creating a Guessing Game

Summary

2. Building Quality Object-Oriented Code

Introduction

Classes and Objects

Constructors

Fields and Class Members

Exercise 2.01: Creating Classes and Objects

Reference Types

Properties

Object Initialization

Comparing Functions and Methods

An Effective Class

Exercise 2.02: Comparing the Area Occupied by Different Shapes

The Four Pillars of OOP

Encapsulation

Inheritance

Polymorphism

What is the Benefit of Polymorphism?

Abstraction

Interfaces

Exercise 2.03: Covering Floor in the Backyard

SOLID Principles in OOP

Single Responsibility Principle

Open-Closed Principle

Liskov Substitution

Interface Segregation

Dependency Inversion

How C# Helps with Object-Oriented Design

Static

Sealed

Partial

Virtual

Internal

Conditional Operators

Ternary Operators

Overloading Operators

Nullable Primitive Types

Generics

Enum

Extension Methods

Struct

Record

Init-Only Setters

ValueTuple and Deconstruction

Exercise 2.04: Creating a Composable Temperature Unit Converter

Activity 2.01: Merging Two Circles

Summary

3. Delegates, Events, and Lambdas

Introduction

Delegates

Defining a Custom Delegate

Exercise 3.01: Defining and Invoking Custom Delegates

The Inbuilt Action and Func Delegates

Assigning Delegates

Invoking a Delegate

Exercise 3.02: Assigning and Invoking Delegates

Multicast Delegates

Exercise 3.03: Invoking a Multicast Delegate

Multicasting with a Func Delegate

What Happens When Things Go Wrong?

Exercise 3.04: Ensuring All Target Methods Are Invoked in a Multicast Delegate

Events

Defining an Event

Exercise 3.05: Publishing and Subscribing to Events

Events or Delegates?

Static Events Can Cause Memory Leaks

Lambda Expressions

Exercise 3.06: Using a Statement Lambda to Reverse Words in a Sentence

Captures and Closures

Activity 3.01: Creating a Web File Downloader

Summary

4. Data Structures and LINQ

Introduction

Data Structures

Lists

Exercise 4.01: Maintaining Order within a List

Queues

Stacks

HashSets

Dictionaries

Exercise 4.02: Using a Dictionary to Count the Words in a Sentence

LINQ

Query Operators

Query Expressions

Deferred Execution

Standard Query Operators

Projection Operations

Select

Anonymous Types

SelectMany

Filtering Operations

Sorting Operations

OrderBy and OrderByDescending

ThenBy and ThenByDescending

Exercise 4.03: Filtering a List of Countries by Continent and Sorting by Area

Partitioning Operations

Grouping Operations

Exercise 4.04: Finding the Most Commonly Used Words in a Book

Aggregation Operations

Quantifier Operations

Join Operations

Using a let Clause in Query Expressions

Activity 4.01: Treasury Flight Data Analysis

Summary

5. Concurrency: Multithreading Parallel and Async Code

Introduction

Running Asynchronous Code Using Tasks

Creating a New Task

Using Task.Factory.StartNew

Using Task.Run

Exercise 5.01: Using Tasks to Perform Multiple Slow-Running Calculations

Coordinating Tasks

Waiting for Tasks to Complete

Exercise 5.02: Waiting for Multiple Tasks to Complete Within a Time Period

Continuation Tasks

Using Task.WhenAll and Task.WhenAny with Multiple Tasks

Exercise 5.03: Waiting for All Tasks to Complete

Asynchronous Programming

Async Lambda Expressions

Canceling Tasks

Exercise 5.04: Canceling Long-Running Tasks

Exception Handling in Async/Await Code

Exercise 5.05: Handling Async Exceptions

The AggregateException Class

IAsyncEnumerable Streams

Parallel Programming

Data Parallelism

Task Parallelism

The Parallel Class

Parallel.For and Parallel.ForEach

Activity 5.01: Creating Images from a Fibonacci Sequence

Summary

6. Entity Framework with SQL Server

Introduction

Creating a Demo Database Before You Start

Modeling Databases Using EF

Connection String and Security

Which One to Choose—EF or EF Core?

Model

DbContext and DbSet

AdventureWorks Database

Exercise 6.01: Reading Stock Locations from AdventureWorks Database

Querying a Database—LINQ to SQL

Query Syntax

The Rest of CRUD

Exercise 6.02: Updating Products and Manufacturers Table

Database First

Revisiting DbContext

Generating DbContext from an Existing Database

Code First and Migrations

Exercise 6.03: Managing Product Price Changes

Pitfalls of EF

Examples Setup

Multiple Adds

Using IEnumerable over IQueryable

Lazy over Eager Loading

Read-Only Queries

Summary of Results

Tools to Help You Spot Problems Early On

Working with a Database in Enterprise

Repository Pattern

Exercise 6.04: Creating a Generic Repository

Testing Data Persistence Logic Locally

In-Memory Database Provider

SQLite Database Provider

A Few Words on Repository

Query and Command Handlers Patterns

Separating the Database Model from the Business Logic (Domain) Model

Activity 6.01: Tracking System for Trucks Dispatched

Summary

7. Creating Modern Web Applications with ASP.NET

Introduction

Anatomy of an ASP.NET Web App

Program.cs and the WebApplication

Middlewares

Logging

Dependency Injection

Exercise 7.01: Creating Custom Logging Middleware

Dependency Lifetimes

Razor Pages

Basic Razor Syntax

File Structure

Exercise 7.02: Creating a Kanban Board with Razor

PageModel

The Life Cycle with Page Handlers

Rendering Reusable Static Code with Tag Helpers

Exercise 7.03: Creating Reusable Components with Tag Helpers

Model Binding

Exercise 7.04: Creating a New Page to Submit Tasks

Validation

Dynamic Behavior with Partial Pages

Exercise 7.05: Refactoring a Tag Helper to a Partial Page with Custom Logic

Activity 7.01: Creating a Page to Edit an Existing Task

View Components

Exercise 7.06: Creating a View Component to Display Task Statistics

Activity 7.02: Writing a View Component to Display Task Log

Summary

8. Creating and Using Web API Clients

Introduction

Browser

Web API

RESTful API

Postman

Client

Octokit

API Key

Azure Text Analytics

Exercise 8.01: Performing Sentimental Text Analysis on Any Text

Your Own Client

HttpClient

HttpClient and IDisposable

OAuth

Real-life Analogy

API Analogy

OAuth App for GitHub

Authorization Header

Basic Authentication

API Key and Personal Access Token

Third-Party Authentication—OAuth2

Request Idempotency

PUT, PATCH, or POST

Exercise 8.02: HttpClient Calling a Star Wars Web API

Activity 8.01: Reusing HttpClient for the Rapid Creation of API Clients

RestSharp

Activity 8.02: The Countries API Using RestSharp to List all Countries

Refit

Activity 8.03: The Countries API Using Refit to List all Countries

Other Ways of Making HTTP Requests

Exercise 8.03: A Strongly Typed HTTP Client for Testing Payments in a PayPal Sandbox

Activity 8.04: Using an Azure Blob Storage Client to Upload and Download Files

Summary

9. Creating API Services

Introduction

ASP.NET Core Web API

Creating a New Project

Web API Project Structure

An In-Depth Look at WeatherForecastController

Responding with Different Status Codes

Exercise 9.01: .NET Core Current Time Service

Bootstrapping a Web API

Dependency Injection

Program.cs and Minimal API

The Inner Workings of the AddLogging Method

The Lifetime of an Injected Component

DI Examples within a Service

Singleton

Scoped

Transient

TryAdd

Manual Injection Using an IoC Container

Exercise 9.02: Displaying Current Time in a Country API Time Zone

OpenAPI and Swagger

Using Swagger Swashbuckle

Error Handling

Request Validation

Configuration

Development Environments and Configuration

Bootstrapping

Calling Another API

RapidAPI

Service Client

DTO and Mapping Using AutoMapper

HttpClient DI

Exercise 9.03: Performing File Operations by Calling Azure Blob Storage

Securing a Web API

Azure Active Directory

JWT

OpenID Connect

Application Registration

Implementing Web API Security

Token Generator App

Configuring Swagger Auth

Troubleshooting Token Validation Errors

Service-Oriented Architecture

Microservice Architecture

Activity 9.01: Implementing the File Upload Service Using Microservice Architecture

Azure Functions

Summary

Preface

About the Book

C# is a powerful and versatile Object-Oriented Programming (OOP) language that can unlock a variety of career paths. But, as with any programming language, learning C# can be challenging. With a wide range of different resources available, it's difficult to know where to start.

That's where The C# Workshop comes in. Written and reviewed by industry experts, it provides a fast-paced, supportive learning experience that will quickly get you writing C# code and building applications. Unlike other software development books that focus on dry, technical explanations of the underlying theory, this workshop cuts through the noise and uses engaging examples to help you learn how each concept is applied in the real world.

As you work through the book, you'll tackle realistic exercises that simulate the types of problems software developers work on every day. These mini-projects include building a random-number guessing game, using the publisher-subscriber model to design a web file downloader, creating a to-do list using Razor Pages, generating images from the Fibonacci sequence using async/await tasks, and developing a temperature unit conversion app that you will then deploy to a production server.

By the end of this book, you'll have the knowledge, skills, and confidence required to advance your career and tackle your ambitious projects with C#.

Audience

This book is for aspiring C# developers. It is recommended that you have a basic knowledge of core programming concepts before you start. Prior experience with another programming language would be beneficial, though it is not absolutely necessary.

About the Authors

Jason Hales has been developing low-latency, real-time applications using various Microsoft technologies since the first release of C# in 2001. He is a keen advocate of design patterns, OO principles, and test-driven practices. When he's not dabbling with code, he likes to spend time with his wife, Ann, and their three daughters in Cambridgeshire, UK.

Almantas Karpavicius is a lead software engineer working in the information and technology company, TransUnion. He has been a professional programmer for over five years. On top of his full-time programming career, Almantas has spent three years teaching programming for free in his free time on Twitch.tv. He is a founder of a C# programming community called C# Inn that boasts over 7000 members and the creator of two free C# boot camps in which he has helped hundreds of people get a start in their careers. He has taken interviews with programming celebrities, such as Jon Skeet, Robert C. Martin (Uncle Bob), Mark Seemann, and was also a part-time Java teacher for a time. Almantas likes talking about software design, clean code, and architecture. He is also interested in Agile (Scrum, in particular) and is a big fan of automated tests, especially those done using BDD. He also holds a two-year Microsoft MVP (https://packt.link/2qUJp).

Mateus Viegas has been working in Software Engineering and Architecture for over a decade, dedicating the last few years to Leadership and Management roles. His main interests in technology are C#, Distributed Systems, and Product Development. A lover of the outdoors, when not working he likes to spend his time either exploring nature with his family, taking photographs, or running.

About the Chapters

Chapter 1, Hello C#, introduces the fundamental concepts of the language, such as variables, constants, loops, and arithmetic and logical operators.

Chapter 2, Building Quality Object-Oriented Code, covers the basics of Object-oriented programming and its four pillars, before introducing the five main principles of clean coding—SOLID. This chapter also covers the latest features in the C# language.

Chapter 3, Delegates, Events, and Lambdas, introduces delegates and events, which form the core mechanism for communicating between objects, and lambda syntax, which offers a way to clearly express the intent of code.

Chapter 4, Data Structures and LINQ, covers the common collection classes that are used to store multiple values and the integrated language LINQ which is designed for querying collections in memory.

Chapter 5, Concurrency: Multithreading Parallel and Async Code, provides an introduction to writing efficient code that is high performing across different scenarios and how to avoid common pitfalls and mistakes.

Chapter 6, Entity Framework with SQL Server, introduces database design and storage using SQL and C# and provides an in-depth look at object-relational mapping using Entity Framework. The chapter also teaches common design patterns for working with databases.

Note

For those who are interested in learning the basics of databases and how to work with PostgreSQL, a reference chapter has been included in the GitHub repository of this book. You can access it at https://packt.link/oLQsL.

Chapter 7, Creating Modern Web Applications with ASP.NET, looks at how to write simple ASP.NET applications and how to use approaches such as server-side rendering and single-page applications to create web applications.

Chapter 8, Creating and Using Web API Clients, introduces APIs and teaches you how to access and consume Web APIs from ASP.NET code.

Chapter 9, Creating API Services, continues with the topic of APIs and teaches you how to create your API services for consumption, and how to secure it. The chapter also introduces you to the concept of microservices.

Note

There are also two bonus chapters (Chapter 10, Automated Testing, and Chapter 11, Production-Ready C#: From Development to Deployment) which you can find at https://packt.link/44j2X and https://packt.link/39qQA, respectively.

You can also find solutions for all activities in this Workshop online at https://packt.link/qclbF.

This book has some conventions set to arrange content efficiently. Read about them in the next section.

Conventions

Block of Code

In the book, a block of code is set as follows:

using System;

namespace Exercise1_01

{

    class Program

    {

        static void Main(string[] args)

        {

            Console.WriteLine("Hello World!");

        }

    }

}

In cases where inputting and executing some code gives an immediate output, this is shown as follows:

dotnet run

Hello World!

Good morning Mars!

Emphasis

Definitions, new terms, and important words are shown like this:

Multithreading is a form of concurrency whereby multiple threads are used to perform operations.

Technical Terms

Language commands within the body of the chapter are indicated in the following manner:

Here, the simplest Task constructor is passed an Action lambda statement, which is the actual target code that you want to execute. The target code writes the message Inside taskA to the console.

Added Information

Essential information is indicated in the following way:

Note

The term Factory is often used in software development to represent methods that help create objects.

Truncation

Long code snippets are truncated and the corresponding names of the code files on GitHub are placed at the top of the truncated code. Permalinks to the entire code are placed below the code snippet, as follows:

HashSetExamples.cs

using System;

using System.Collections.Generic;

namespace Chapter04.Examples

{

}

You can find the complete code here: http://packt.link/ZdNbS.

Before you dive into the power of the C# language, you will need to install the .NET runtime and the C# development and debugging tools.

Before You Begin

You can either install the full Visual Studio Integrated Development Environment (IDE), which offers a fully featured code editor (this is a costly license) or you can install Visual Studio Code (VS Code), Microsoft's lightweight cross-platform editor. The C# Workshop targets the VS Code editor as this does not require a license fee and works seamlessly across multiple platforms.

Installing VS Code

Visit the VS Code site at https://code.visualstudio.com and download it for Windows, macOS, or Linux, following the installation instructions for your preferred platform.

Note

It is better to check the Create a Desktop Icon checkbox for ease of use.

VS Code is free and open source. It supports multiple languages and needs to be configured for the C# language. Once VS Code is installed, you will need to add the C# for Visual Studio Code (powered by OmniSharp) extension to support C#. This can be found at https://marketplace.visualstudio.com/items?itemName=ms-dotnettools.csharp. To install the C# extension, follow the per-platform instructions:

Open the Extension tab and type C#.

Note

If you do not want to directly install the C# extension from the website, install it from VS code itself.

Select the first selection, that is, C# for Visual Studio Code (powered by OmniSharp).Click on the Install button.Restart VS Code:

Figure 0.1: Installing the C# extension for VS Code

You will see that the C# extension gets successfully installed on VS Code. You have now installed VS Code on your system.

The next section will cover how VS Code can be used as you move between the book chapters.

Moving Between Chapters in VS Code

To change the default project to build (whether it is an activity, exercise, or demo), you will need to point to these exercise files:

tasks.json / tasks.argslaunch.json / configurations.program

There are two different patterns of exercise that you should be aware of. Some exercises have a project of their own. Others have a different main method. The main method of a single project per exercise can be configured like this (in this example for Chapter 3, Delegates, Events, and Lambdas, you are configuring Exercise02 to be the build and launch points):

launch.json

{

    "version": "0.2.0",

    "configurations": [

        {

            "name": ".NET Core Launch (console)",

            "type": "coreclr",

            "request": "launch",

            "preLaunchTask": "build",

            "program": "${workspaceFolder}/Exercises/ /Exercise02/bin/Debug/net6.0/Exercise02.exe",

            "args": [],

            "cwd": "${workspaceFolder}",

            "stopAtEntry": false,

            "console": "internalConsole"

        }

    ]

}

tasks.json

{

    "version": "2.0.0",

    "tasks": [

        {

            "label": "build",

            "command": "dotnet",

            "type": "process",

            "args": [

                "build",

                "${workspaceFolder}/Chapter05.csproj",

                "/property:GenerateFullPaths=true",

                "/consoleloggerparameters:NoSummary"

            ],

            "problemMatcher": "$msCompile"

        },

    ]

}

One project for each exercise (for example, Chapter05 Exercise02) can be configured like this:

launch.json

{

    "version": "0.2.0",

    "configurations": [

        {

            "name": ".NET Core Launch (console)",

            "type": "coreclr",

            "request": "launch",

            "preLaunchTask": "build",

            "program": "${workspaceFolder}/bin/Debug/net6.0/Chapter05.exe",

            "args": [],

            "cwd": "${workspaceFolder}",

            "stopAtEntry": false,

            "console": "internalConsole"

        }

    ]

}

tasks.json

{

    "version": "2.0.0",

    "tasks": [

        {

            "label": "build",

            "command": "dotnet",

            "type": "process",

            "args": [

              "build",

              "${workspaceFolder}/Chapter05.csproj",

              "/property:GenerateFullPaths=true",

              "/consoleloggerparameters:NoSummary",

              "-p:StartupObject=Chapter05.Exercises.Exercise02.Program",

            ],

            "problemMatcher": "$msCompile"

        },

    ]

}

Now that you are aware of launch.json and tasks.json, you can proceed to the next section which details the installation of the .NET developer platform.

Installing the .NET Developer Platform

The .NET developer platform can be downloaded from https://dotnet.microsoft.com/download. There are variants for Windows, macOS, and Docker on Linux. The C# Workshop book uses .NET 6.0.

Follow the steps to install the .NET 6.0 platform on Windows:

Select the Windows platform tab:

Figure 0.2: .NET 6.0 download window

Click on the Download .NET SDK x64 option.

Note

The screen shown in Figure 0.2 may change depending on the latest release from Microsoft.

Open and complete the installation according to the respective OS installed on your system.Restart the computer after the installation.

Follow the steps to install the .NET 6.0 platform on macOS:

Select the macOS platform tab (Figure 0.2).Click on the Download .NET SDK x64 option.

After the download is complete, open the installer file. You should have a screen similar to Figure 0.3:

Figure 0.3: The macOS installation starting screen

Click on the Continue button.

The following screen will confirm the amount of space that will be required for the installation:

Click on the Install button to continue:

Figure 0.4: Window displaying the disk space required for installation

You will see a progress bar moving on the next screen:

Figure 0.5: Window showing the Installation progress

Soon after the installation is finalized, you'll have a success screen (Figure 0.6):

Figure 0.6: Window showing the installation as complete

In order to check whether the installation was a success, open your Terminal app and type:

dotnet –list-sdks

This will check the version of .NET installed on your machine. Figure 0.7 shows the output where your installed SDKs will be listed:

Figure 0.7: Checking the installed .NET SDKs in Terminal

With these steps, you can install the .NET 6.0 SDK on your machine and check the installed version.

Note

Net 6.0 installation steps for Linux are not included as they are like Windows and macOS.

Before proceeding further, it is important to know about .NET 6.0 features.

The .NET 6.0 Features Found in Windows, macOS, and Linux

Windows

.NET 6.0: This is the latest long-term support (LTS) version recommended for Windows. It can be used for building many different types of applications..NET Framework 4.8: This is a Windows-only version for building any type of app to run on Windows only.

macOS

.NET 6.0: This is the LTS version recommended for macOS. It can be used for building many different types of applications. Choose the version that is compatible with the processor of your Apple Computer—x64 for Intel chips and ARM64 for Apple chips.

Linux

.NET 6.0: This is the LTS version recommended for Linux. It can be used for building many different types of applications.

Docker

.NET images: This developer platform can be used for building different types of applications..NET Core images: This offers lifetime support for building many types of applications..NET framework images: These are Windows-only versions of .NET for building any type of app that runs on Windows.

With .NET 6.0 installed on your system, the next step is to configure projects using CLI.

.NET Command-Line Interface (CLI)

Once you have installed .NET, the CLI can be used to create and configure projects for use with VS Code. To launch the .NET CLI, run the following at the command prompt:

dotnet

If .NET is installed correctly, you will see the following message on your screen:

Usage: dotnet [options]

Usage: dotnet [path-to-application]

Once you have the CLI installed to configure projects with VS Code, you need to know about the powerful open source object-relational database system that uses and extends the SQL language that is, PostgreSQL.

Note

You will first go through the instructions to install PostgreSQL for Windows followed by macOS, and then by Linux.

PostgreSQL Installation for Windows

PostgreSQL has been used in Chapter 6, Entity Framework with SQL Server. Before you proceed with that chapter, you must install PostgreSQL on your system using the following steps:

Go to https://www.enterprisedb.com/downloads/postgres-postgresql-downloads and download the latest version installer for Windows:

Figure 0.8: Latest PostgreSQL versions for each platform

Note

The screen shown in Figure 0.8 may change depending upon the latest release from the vendor.

Open the downloaded interactive installer and click the Next button. The Setup PostgreSQL screen gets displayed:

Figure 0.9: Welcome screen for PostgreSQL upload

Click on the Next button to move to the next screen which asks for the installation directory details:

Figure 0.10: PostgreSQL default installation directory

Leave the default Installation Directory unchanged and click the Next button.Select the following from the list in Figure 0.11:PostgreSQL Server refers to the database.pgAdmin 4 is the database management tool.Stack Builder is the PostgreSQL environment builder (optional).Command Line Tools work with the database using a command line.

Figure 0.11: The PostgreSQL components selected to proceed

Then click the Next button.In the next screen, the Data Directory screen asks you to enter the directory for storing your data. So, enter the data directory name:

Figure 0.12: The directory for storing data

Once you have entered the data directory, click on the Next button to continue. The next screen asks you to enter the password.Enter the new Password.Retype the password beside Retype password for the database superuser:

Figure 0.13: Providing password for database superuser

Then click the Next button to continue.The next screen displays the Port as 5432. Use the default port—that is, 5432:

Figure 0.14: Selecting Port

Click the Next button.The Advanced Options screen asks you to type the locale for the Database cluster. Leave it as [Default locale]:

Figure 0.15: Selecting the locale for the Database cluster

Then click the Next button.When the Preinstallation Summary screen gets displayed, click the Next button to go ahead:

Figure 0.16: Setup window showing ready to install message

Continue selecting the Next button (leaving the default settings unchanged) until the installation process begins.Wait for it to complete. On completion, the Completing the PostgreSQL Setup Wizard screen gets displayed.Uncheck the Launch Stack Builder at exit option:

Figure 0.17: Installation complete with Stack Builder unchecked

The Stack Builder is used to download and install additional tools. The default installation contains all tools needed for the exercises and activities.

Finally, click the Finish button.Now open pgAdmin4 from Windows.Enter a master Password for connecting to any database inside PostgreSQL in the Set Master Password window:

Figure 0.18: Setting Master Password for connecting to a PostgreSQL server

Note

It is better to type a password that you can easily memorize as it will be used to manage all your other credentials.

Next click the OK button.On the left side of the pgadmin window, expand the Server by clicking the arrow beside it.You will be asked to enter your PostgreSQL server password. Type the same password that you entered in Step 22.Do not click Save password for security reasons:

Figure 0.19: Setting the postgres user password for the PostgreSQL server

PostgreSQL server password is the password you will use when connecting to the PostgreSQL server and using the postgres user.

Finally click the OK button. You will see the pgAdmin dashboard:

Figure 0.20: pgAdmin 4 dashboard window

In order to explore the pgAdmin dashboard, move to the Exploring pgAdmin Dashboard section.

PostgreSQL Installation for macOS

Install PostgreSQL on your macOS using the following steps:

Visit the official site of the Postgres app to download and install PostgreSQL on your mac platform: https://www.enterprisedb.com/downloads/postgres-postgresql-downloads.Download the latest PostgreSQL for macOS:

Note

The following screenshots were taken for version 14.4 on macOS Monterey (version 12.2).

Figure 0.21: Installation page for PostgreSQL

Once you have downloaded the installer file for macOS, double-click the installer file to launch the PostgreSQL Setup Wizard:

Figure 0.22: Launching the PostgreSQL setup wizard

Select the location where you want PostgreSQL installed:

Figure 0.23: Selecting the installation directory

Click on the Next button.In the next screen, select the following components for installation:PostgreSQL ServerpgAdmin 4Command Line ToolsUncheck the Stack Builder component:

Figure 0.24: Selecting the components for installation

Once you have selected the options, click on the Next button.Specify the data directory in which PostgreSQL will store the data:

Figure 0.25: Specifying the data directory

Click on the Next button.Now set a Password for the Postgres database superuser:

Figure 0.26: Setting the password

Make sure to note down the password safely for logging in to the PostgreSQL database.

Click on the Next button.

Set the port number where you want to run the PostgreSQL server. Here the default Port number is set as 5432:

Figure 0.27: Specifying the port number

Click on the Next button.Select the locale to be used by PostgreSQL. Here, [Default locale] is the locale selected for macOS:

Figure 0.28: Selecting the locale specification

Click on the Next button.In the next screen, check the installation details:

Figure 0.29: Pre Installation summary page

Finally, click on the Next button to start the installation process of the PostgreSQL database server on your system:

Figure 0.30: Ready to Install page before starting the installation process

Wait for a few moments for the installation process to complete:

Figure 0.31: Setup Installation in progress

When prompted, click the Next button. The next screen displays the message that the PostgreSQL installation is complete on your system:

Figure 0.32: Success message showing the setup as complete

Click the Finish button once the installation gets complete.Now load the database in the PostgreSQL server.Double-click on the pgAdmin 4 icon to launch it from your Launchpad.Enter the password for the PostgreSQL user that you had set during the installation process.Then click the OK button. You will now see the pgAdmin dashboard.

This completes the installation of PostgreSQL for the macOS. The next section will familiarize you with the PostgreSQL interface.

Exploring pgAdmin Dashboard

Once you have installed PostgreSQL in Windows and macOS, follow these steps to grasp the interface better:

Open pgAdmin4 from Windows/ macOS (in case pgAdmin is not open on your system).Click on the Servers option on the left:

Figure 0.33: Clicking on Servers to create a database

Right-click on PostgreSQL 14.Then click on the Create option.Choose the Database… option to create a new database:

Figure 0.34: Creating a new database

This will open a Create – Database window.

Enter the database name, as TestDatabase.Select the Owner of the database or leave it as default. For now, just use the Owner as postgres:

Figure 0.35: Selecting the owner of the database

Then click on the Save button. This will create a database.Right-click on Databases and choose the Refresh button:

Figure 0.36: Clicking the Refresh… button after right-clicking Databases

A database with the name TestDatabase is now displayed within the dashboard:

Figure 0.37: TestDatabase ready for use

Now your database is ready to be used for Windows and Mac environments.

PostgreSQL Installation on Ubuntu

In this example, you are using Ubuntu 20.04 for installation. Perform the following steps to do so:

In order to install PostgreSQL, open your Ubuntu terminal first.Make sure to update your repository using the following command:

$ sudo apt update

Install the PostgreSQL software along with additional packages using the following command (recommended):

$ sudo apt install postgresql postgresql-contrib

Note

To install only PostgreSQL (not recommended without additional packages), use the command $ sudo apt install postgresql and then press Enter.

This installation process creates a user account called postgres that has the default Postgres role.

Accessing the postgres User Account with the postgres Role

There are two ways to start the PostgreSQL CLI using the postgres user account:

Option 1 is as follows:

To log in as a postgres user, use the following command:

$ sudo -i -u postgres

Access the CLI by using the following command:

$ psql

Note

Sometimes, while executing the preceding command, a psql error may be displayed as could not connect to server: No such file or directory. This is because of a port issue on your system. Due to this port blockage, the PostgreSQL application may not work. You can try the command again after some time.

To quit the CLI, use the following command:

$ \q

Option 2 is as follows:

To log in as a postgres user, use the following command:

$ sudo -u postgres psql

To quit the CLI, use the following command:

$ \q

Verifying the postgres User Account as a postgres User Role

To verify the user account, log in and use the conninfo command:

$ sudo -u postgres psql

$ \conninfo

$ \q

Using this command, you can ensure that you are connected to the postgres database as the postgres user via port 5432. If you don't want to use the default user, postgres, you can create a new user for you.

Accessing a New User and Database

Create a new user by using the following command and pressing Enter:

$ sudo -u postgres createuser –interactive

The preceding command will ask the user to add the name of the role and its type.

Enter the name of the role, for example, testUser.Next, enter y when prompted to set a new role to be a superuser:

Prompt:

Enter the name of the role to add: testUser

Shall the new role be a superuser? (y/n) y

This will create a new user with the name testUser.

Create a new database with the name testdb using the following command:

$ sudo -u postgres createdb testdb

Log in to the newly created user account using the following command:

$ sudo -u testUser psql -d testdb

Use the following command to check the connection details:

$ \conninfo

To quit the CLI, use the following command:

$ \q

Using this command, you can ensure that you are connected to the testdb database as the testUser user via port 5432.

With these steps, you have completed the PostgreSQL installation for Ubuntu.

Downloading the Code

Download the code from GitHub at https://packt.link/sezEm. Refer to these files for the complete code.

The high-quality color images used in this book can be found at https://packt.link/5XYmX.

If you have any issues or questions about installation, please email us at [email protected].

1. Hello C#