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 transactions to save or revert changes

A SQL transaction is a grouping of one or more changes to the database. Transactions help ensure a consistent state in your database. The common terms in SQL transactions are COMMIT and ROLLLBACK. Commit makes the changes permanent and rollback cancels the changes.

There are four properties of transactions to keep in mind:

  • Atomicity: This ensures all changes in a transaction are completed successfully. If they are successful, the changes are committed. If any change isn't successful, all the changes are rolled back.
  • Consistency: This ensures any changes can't violate the database's integrity, including constraints. Changes interrupted by errors due to violations of database integrity are rolled back. This includes any changes that don't violate database integrity.
  • Isolation: All transactions are isolated from...