Book Image

The SQL Workshop

By : Frank Solomon, Prashanth Jayaram, Awni Al Saqqa
Book Image

The SQL Workshop

By: Frank Solomon, Prashanth Jayaram, Awni Al Saqqa

Overview of this book

Many software applications are backed by powerful relational database systems, meaning that the skills to be able to maintain a SQL database and reliably retrieve data are in high demand. With its simple syntax and effective data manipulation capabilities, SQL enables you to manage relational databases with ease. The SQL Workshop will help you progress from basic to advanced-level SQL queries in order to create and manage databases successfully. This Workshop begins with an introduction to basic CRUD commands and gives you an overview of the different data types in SQL. You'll use commands for narrowing down the search results within a database and learn about data retrieval from single and multiple tables in a single query. As you advance, you'll use aggregate functions to perform calculations on a set of values, and implement process automation using stored procedures, functions, and triggers. Finally, you'll secure your database against potential threats and use access control to keep your data safe. Throughout this Workshop, you'll use your skills on a realistic database for an online shop, preparing you for solving data problems in the real world. By the end of this book, you'll have built the knowledge, skills and confidence to creatively solve real-world data problems with SQL.
Table of Contents (13 chapters)

Introduction

So far, whenever we have wanted to see the results, we have used the Select * syntax either by entering that query directly, or by generating it using the appropriate option in the application's menu. This displayed the entire table. However, when we want to retrieve data from the database, we are often not interested in the entire dataset; we are only looking for specific details. For example, the Packt database contains details of all the books published by Packt. It might include columns such as Book Name, ISBN, Author Name, Author ID, Author Email, Page Count, and Price. But if we wanted to send out a survey to all the authors who have written for Packt, all we would require is the author's name and their email address:

Figure 4.1: A sample table containing all the details of a book

This is all we require:

Figure 4.2: The required details

Queries help us do just this. Using the SELECT statement, we can pick...