Book Image

Learn SQL Database Programming

By : Josephine Bush
5 (1)
Book Image

Learn SQL Database Programming

5 (1)
By: Josephine Bush

Overview of this book

SQL is a powerful querying language that's used to store, manipulate, and retrieve data, and it is one of the most popular languages used by developers to query and analyze data efficiently. If you're looking for a comprehensive introduction to SQL, Learn SQL Database Programming will help you to get up to speed with using SQL to streamline your work in no time. Starting with an overview of relational database management systems, this book will show you how to set up and use MySQL Workbench and design a database using practical examples. You'll also discover how to query and manipulate data with SQL programming using MySQL Workbench. As you advance, you’ll create a database, query single and multiple tables, and modify data using SQL querying. This SQL book covers advanced SQL techniques, including aggregate functions, flow control statements, error handling, and subqueries, and helps you process your data to present your findings. Finally, you’ll implement best practices for writing SQL and designing indexes and tables. By the end of this SQL programming book, you’ll have gained the confidence to use SQL queries to retrieve and manipulate data.
Table of Contents (24 chapters)
Section 1: Database Fundamentals
Section 2: Basic SQL Querying
Section 3: Advanced SQL Querying
Section 4: Presenting Your Findings
Section 5: SQL Best Practices

Using common table expressions

A common table expression (CTE) is a container for a single SQL statement that will allow you to query a temporary result set. A CTE allows you to create complex queries in a more readable way. It may be beneficial to use a CTE instead of subqueries because it's easier to read and understand later. CTEs can also be used instead of creating a view. To create a view, you need elevated permissions in a database, but you won't need any additional permissions to use a CTE. Views will be covered in more detail in Chapter 12, Programmable Objects. Additionally, CTEs can help you run recursive queries.

Using non-recursive CTEs

The syntax for a single non-recursive CTE is as follows: