Book Image

MySQL 8 Cookbook

By : Karthik Appigatla
Book Image

MySQL 8 Cookbook

By: Karthik Appigatla

Overview of this book

MySQL is one of the most popular and widely used relational databases in the World today. The recently released MySQL 8 version promises to be better and more efficient than ever before. This book contains everything you need to know to be the go-to person in your organization when it comes to MySQL. Starting with a quick installation and configuration of your MySQL instance, the book quickly jumps into the querying aspects of MySQL. It shows you the newest improvements in MySQL 8 and gives you hands-on experience in managing high-transaction and real-time datasets. If you've already worked with MySQL before and are looking to migrate your application to MySQL 8, this book will also show you how to do that. The book also contains recipes on efficient MySQL administration, with tips on effective user management, data recovery, security, database monitoring, performance tuning, troubleshooting, and more. With quick solutions to common and not-so-common problems you might encounter while working with MySQL 8, the book contains practical tips and tricks to give you the edge over others in designing, developing, and administering your database effectively.
Table of Contents (20 chapters)
Title Page
Dedication
Packt Upsell
Contributors
Preface
Index

Joining tables


So far you have looked at inserting and retrieving data from a single table. In this section, we will discuss how to combine two or more tables to retrieve the results. 

A perfect example is that you want to find the employee name and department number of a employee with emp_no: 110022:

  • The department number and name are stored in the departments table
  • The employee number and other details, such as first_name and last_name, are stored in the employees table
  • The mapping of employee and department is stored in the dept_manager table

If you do not want to use JOIN, you can do this:

  1. Find the employee name with emp_no as 110022 from the employee table:
mysql> SELECT emp.emp_no, emp.first_name, emp.last_name 
FROM employees AS emp  
WHERE  emp.emp_no=110022;
+--------+------------+------------+
| emp_no | first_name | last_name  |
+--------+------------+------------+
| 110022 | Margareta  | Markovitch |
+--------+------------+------------+
1 row in set (0.00 sec)
  1. Find the department...