MySQL Reference Manual

Data Definition: CREATE, DROP, ALTER

CREATE DATABASE Syntax

CREATE DATABASE [IF NOT EXISTS] db_name

CREATE DATABASE creates a database with the given name. Rules for allowable database names are given in Section 6.1.2. An error occurs if the database already exists and you didn’t specify IF NOT EXISTS.

Databases in MySQL are implemented as directories containing files that correspond to tables in the database. Because there are no tables in a database when it is initially created, the CREATE DATABASE statement only creates a directory under the MySQL data directory.

You can also create databases with mysqladmin. See Section 4.8.

DROP DATABASE Syntax

DROP DATABASE [IF EXISTS] db_name

DROP DATABASE drops all tables in the database and deletes the database. If you do a DROP DATABASE on a symbolic linked database, both the link and the original database are deleted. Be very careful with this command!

DROP DATABASE returns the number of files that were removed from the database directory. Normally, this is three times the number of tables because normally each table corresponds to a .MYD file, a .MYI file, and a .frm file.

The DROP DATABASE command removes from the given database directory all files with the following extensions:

Ext	Ext	Ext	Ext
.BAK	.DAT	.HSH	.ISD
.ISM	.ISM	.MRG	.MYD
.MYI	.db	.frm

All subdirectories that consists of 2 digits (RAID directories) are also removed.

In MySQL Version 3.22 or later, you can use the keywords IF EXISTS to prevent an error from occurring ...