Sign In Start Free Trial
Account

Add to playlist

Create a Playlist

Modal Close icon
You need to login to use this feature.
  • Book Overview & Buying Learning PHP 7
  • Table Of Contents Toc
Learning PHP 7

Learning PHP 7

By : Antonio L Zapata (GBP)
3.4 (10)
close
close
Learning PHP 7

Learning PHP 7

3.4 (10)
By: Antonio L Zapata (GBP)

Overview of this book

PHP is a great language for building web applications. It is essentially a server-side scripting language that is also used for general purpose programming. PHP 7 is the latest version with a host of new features, and it provides major backwards-compatibility breaks. This book begins with the fundamentals of PHP programming by covering the basic concepts such as variables, functions, class, and objects. You will set up PHP server on your machine and learn to read and write procedural PHP code. After getting an understanding of OOP as a paradigm, you will execute MySQL queries on your database. Moving on, you will find out how to use MVC to create applications from scratch and add tests. Then, you will build REST APIs and perform behavioral tests on your applications. By the end of the book, you will have the skills required to read and write files, debug, test, and work with MySQL.
Table of Contents (12 chapters)
close
close
11
Index

Keys and constraints


Now that we have our main tables defined, let's try to think about how the data inside would look. Each row inside a table would describe an object, which may be either a book or a customer. What would happen if our application has a bug and allows us to create books or customers with the same data? How will the database differentiate them? In theory, we will assign IDs to customers in order to avoid these scenarios, but how do we enforce that the ID not be repeated?

MySQL has a mechanism that allows you to enforce certain restrictions on your data. Other than attributes such as NOT NULL or UNSIGNED that you already saw, you can tell MySQL that certain fields are more special than others and instruct it to add some behavior to them. These mechanisms are called keys, and there are four types: primary key, unique key, foreign key, and index. Let's take a closer look at them.

Primary keys

Primary keys are fields that identify a unique row from a table. There cannot be two...

CONTINUE READING
83
Tech Concepts
36
Programming languages
73
Tech Tools
Icon Unlimited access to the largest independent learning library in tech of over 8,000 expert-authored tech books and videos.
Icon Innovative learning tools, including AI book assistants, code context explainers, and text-to-speech.
Icon 50+ new titles added per month and exclusive early access to books as they are being written.
Learning PHP 7
notes
bookmark Notes and Bookmarks search Search in title playlist Add to playlist download Download options font-size Font size

Change the font size

margin-width Margin width

Change margin width

day-mode Day/Sepia/Night Modes

Change background colour

Close icon Search
Country selected

Close icon Your notes and bookmarks

Confirmation

Modal Close icon
claim successful

Buy this book with your credits?

Modal Close icon
Are you sure you want to buy this book with one of your credits?
Close
YES, BUY

Submit Your Feedback

Modal Close icon
Modal Close icon
Modal Close icon