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

In the previous chapter, we learned how to extract data from a specific table and sort it. However, in practice, we come across a lot of scenarios where we need to filter our results based on certain criteria and conditions. Consider the example of a table containing the details of all the books available from Packt, from which we want to find the names and ISBNs of all the books that cost more than $10. This scenario is illustrated in the following figures:

Figure 5.1: Applying a filter to retrieve books that cost more than $10

The relevant columns are shown in the following table. The filtered result will look something like the second table in the following figure:

Figure 5.2: Result after filtering and retrieving books that cost more than $10

In SQL, the WHERE clause allows us to apply the filter functionality. In this chapter, we will dig deep into using the WHERE clause in our queries by combining and adding different...