---
name: "RoPkg::DB"
section: "3pm"
platform: "linux"
package: "libropkg-perl"
version: "0.4-1.3"
release: "Debian 11 (Bullseye)"
platforms: ["linux"]
url: "https://new.carta.tech/RoPkg::DB"
---

# RoPkg::DB(3pm)

A Singleton database pool class

## NAME

RoPkg::DB - 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

None known to the author

## SEE ALSO

RoPkg::DBObject RoPkg::Exceptions RoPkg::Utils

## AUTHOR

Subredu Manuel \<diablo@iasi.roedu.net\>

## LICENSE AND COPYRIGHT

Copyright (C) 2005 Subredu Manuel.  All Rights Reserved. This module is free software; you can redistribute it  and/or modify it under the same terms as Perl itself. The LICENSE file contains the full text of the license.