Table of Contents for

MySQL in a Nutshell, 2nd Edition

Use this method to establish a connection to MySQL and to select the default database. The first argument is a list of required values separated by colons: the module (DBI), the driver (mysql) for a MySQL server, and the database name. The hostname or IP address and port number are optional. The second argument is the username and the third is the user’s password. You can substitute any of these settings or values with variables—just be sure to enclose each argument containing variables with double quotes so that the values will be interpolated. Finally, you may give attributes in the fourth argument. Here is an example:

my $dbh = DBI->connect('DBI:mysql:bookstore:localhost',
   'paola','caporalle1017', {AutoCommit=>0});

In this excerpt, Perl is connecting to the MySQL server with the username paola and the password caporalle1017, with the database bookstore. The attribute AutoCommit is set to off so that changes to the data may be undone using rollback(). See the end of this chapter for a list of attributes.

If you don’t specify the username or the user’s password (i.e., if undef is given instead), the value of the environment variables, DBI_USER and DBI_PASS, will be used if they are defined.