man RoPkg::DB (3): A Singleton database pool class

VERSION

0.1.12

DESCRIPTION

RoPkg::DB is a database pool class. Using this class you can have access to multiple databases (no matter what kind of database), from a single object. RoPkg::DB is ideal in persistent environments because at base, is a singleton class. This class is intensively used by Simba but it can be used in any other project.

SYNOPSIS

use RoPkg::DB;

sub main {
my $dbp = new RoPkg::DB();

eval {
$dbp->Add('dbi:mysql:database=mysql;host=localhost',
'root',
'',
'local');
$dbp->Add('dbi:mysql:database=somedb;host=somehost',
'username',
'mypass',
'somedb');
};

die($@->package . ' said: ' . $@->message) if ref($@);

print 'Conn to localhost is:',$dbp->db_local,$/,
'Conn to remote is:',$dbp->db_somedb,$/;

$dbp->Del('somedb');

}

SUBROUTINES/METHODS

All methods (besides new), raise OutsideClass exception when are not called within a class instance. Also, each method may raise diferent exceptions from one case to another. Please read the documentation for each method to find out what are the exceptions raised by each method.

new()

new is the contructor of the class. It does not do anything.

Add($dsn, $dbuser, $dbpass, $conn_name)

add and initialize a new connection to the pool. $dsn must be in the DBI format. $dsn and $dbpass are the username and password used to connect to the database. $conn_name is the method who will be used to access the database handle. Please note that the method that will be created will be prefixed with ``db_'' .

Example:

 $dbp->Add('dbi:mysql:database=mysql;host=localhost','root',q{},'local');

The method that will be used to get the database handle for this connection is db_local .

Add() may raise the following exceptions:

*) Param::Missing
*) DB::ConnExists
*) DB::Connect

Param::Missing is raised when $dsn, $dbuser or $conn_name are not defined. DB::ConnExists is raised when a connection with the name $conn_name already exists. DB::Connect is raised when the connection with the database could not be established. Besides this exceptions, each database handler has RaiseError set to 1 and PrintError set to 0. Also, when errors occurs, DBI will raise a DB exception. The method always returns 1.

Del($name)

removes the connection named $name from the pool. The connection is closed first in a civilised manner. If the connection $name is not found, DB::ConnNotFound is raised.

Has($name)

Returns 0 if the connection named $name does not exists, 1 otherwise. Param::Missing exception is raised if $name is not defined.

Reconnect($name)

Force a reconnect of the connection named $name. If $name is not defined, Param::Missing is raised. If a connection named $name does not exists, DB::ConnNotFound is raised. This method always returns 1.

TableExists($name, $table_name)

Returns 1 if the table $table_name exists in the database specified by the connection named $name, 0 otherwise. If $name or $table_name parameters are not defined, a Param::Missing exception is raised. If the connection $name does not exists, DB::ConnNotFound is raised.

DEPENDENCIES

RoPkg::DB requires perl 5.008 or later and the following modules:

RoPkg >= 0.4.4
DBI
Class::Singleton
English

DIAGNOSTICS

This module comes with tests. To run the tests, unpack the source and run 'make test'

PERL CRITIC

This module is perl critic level 2 compliant (with 1 exception)

CONFIGURATION AND ENVIRONMENT

This module does not use any configuration files or environment variables. The used modules however may use such things. Please refer to each module man page for more information.

INCOMPATIBILITIES

None known to the author

BUGS AND LIMITATIONS