Learning Mysql

CHAPTER 5
Basic SQL
SQL is the only database language in widespread use. Since it was first proposed in the early sit has been criticized, changed, extended, and finally adopted by all the players in the database market. The latest standard is SQL-2003—the 2003 denotes its release year—but the version supported by most database servers is more closely related to its predecessors, SQL and SQL. MySQL supports most of the features of
SQL-1992 and many from the newer SQL standards, but it also includes many nonstandard features that give more control over the database server and how it evaluates queries and returns results.
This chapter introduces the basics of MySQL’s implementation of SQL. We show you how to read data from a database with the
SELECT
statement, and how to choose what data is returned and the order it is displayed in. We also show you the basics of modifying your databases with the
INSERT
statement to add data,
UPDATE
to change, and
DELETE
to remove it. We also explain how to use the nonstandard SHOW TABLES
and
SHOW
COLUMNS
statements to explore your database.
Following our example-based approach, we use the music database designed in Chapter to show you how to work with an existing database, and use basic SQL to read and write data. In Chapter 6, we’ll explain how to create the music database on your
MySQL server. We’ll also show how you can create your own database and tables, and modify the structure of existing ones. In Chapters 7 and 8, you’ll learn about some advanced features of the SQL variant used by MySQL.

Download 4.24 Mb.

Share with your friends: