Book Image

Learning PHP 7

By : Antonio L Zapata (GBP)
Book Image

Learning PHP 7

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 (17 chapters)
Learning PHP 7
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Querying data


It took quite a lot of time, but we are finally in the most exciting—and useful—section related to databases: querying data. Querying data refers to asking MySQL to return rows from the specified table and optionally filtering these results by a set of rules. You can also choose to get specific fields instead of the whole row. In order to query data, we will use the SELECT command, as follows:

mysql> SELECT firstname, surname, type FROM customer;
+-----------+---------+---------+
| firstname | surname | type    |
+-----------+---------+---------+
| Han       | Solo    | premium |
| James     | Kirk    | basic   |
+-----------+---------+---------+
2 rows in set (0.00 sec)

One of the simplest ways to query data is to specify the fields of interest after SELECT and specify the table with the FROM keyword. As we did not add any filters—mostly known as conditions—to the query, we got all the rows there. Sometimes, this is the desired behavior, but the most common thing to do...