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 saw how the various types of SQL joins can connect multiple tables in a single SELECT query. This powerful technique gives us fine-grained control over the data that our SQL queries return. However, SQL offers much more. In this chapter, we'll use the PACKT_ONLINE_SHOP database to see how subqueries, CASE statements, and views boost the flexibility and power of SQL in an efficient, intuitive way. Like joins, subqueries can relate different tables together in the same SQL query, but compared to queries involving multiple outer joins and unions, subqueries can offer a simpler, cleaner query structure. This can make the development and maintenance of the code easier. CASE statements offer a clean, efficient way for a query to handle decisions, depending on the defined conditions that occur in the query. Views provide an efficient, effective way to group multiple tables together in a symbolic table that's available for use by other queries...