MySQL Cookbook, 4th Edition

Chapter 4. Writing MySQL-Based Programs

4.0 Introduction

This chapter discusses how to use MySQL from within the context of a general-purpose programming language. It covers basic application programming interface (API) operations that are fundamental to and form the basis for the programming recipes developed in later chapters. These operations include connecting to the MySQL server, executing statements, and retrieving the results.

MySQL-based client programs can be written using many languages. This book covers the languages and interfaces shown in Table 4-1 (for information on obtaining the interface software, see the Preface).

Table 4-1. Languages and interfaces covered in this book

Language	Interface
Perl	Perl DBI
Ruby	Mysql2 gem
PHP	PDO
Python	DB-API
Go	Go sql
Java	JDBC

MySQL client APIs provide the following capabilities, each covered in a section of this chapter:

Connecting to the MySQL server, selecting a database, and disconnecting from the server

Every program that uses MySQL must first establish a connection to the server. Most programs also select a default database, and well-behaved MySQL programs close the connection to the server when they’re done with it.

Checking for errors

Any database operation can fail. If you know how to find out when that occurs and why, you can take appropriate action, such as terminating the program or informing the user of the problem.

Executing SQL statements and retrieving results

The point of connecting to a database server is to execute SQL statements. Each ...