MQdb::Database.3pm

Langue: en

Version: 2009-05-30 (debian - 07/07/09)

Section: 3 (Bibliothèques de fonctions)

Sommaire

NAME - MQdb::Database

DESCRIPTION

Generalized handle on an DBI database handle. Used to provide an instance which holds connection information and allows a higher level get_connection/ disconnect logic that persists above the specific DBI connections. Also provides a real object for use with the rest of the toolkit.

SUMMARY

MQdb::Database provides the foundation of the MappedQuery system. Databases are primarily specified with a URL format. The URL format includes specification of a driver so this single method can select among the supported DBD drivers. Currently the system supports MYSQL, Oracle, and SQLite. The URL also allows the system to provide the foundation for doing federation of persisted objects. Each DBObject contains a pointer to the Database instance where it is stored. With the database URL and internal database ID, each object is defined in a global space.

Attributes of MQdb::Database
  driver   :  mysql, oracle, sqlite (default mysql)
  user     :  username if the database requires
  password :  password if the database requires
  host     :  hostname of the database server machine 
  port     :  IP port of the database if required 
              (mysql default is 3306)
  dbname   :  database/schema name on the database server
              for sqlite, this is the database file

Example URLS
  mysql://<user>:<pass>@<host>:<port>/<database_name>
  mysql://<host>:<port>/<database_name>
  mysql://<user>@<host>:<port>/<database_name>
  mysql://<host>/<database_name>
  oracle://<user>:<pass>@/<database_name>
  oracle://<user>:<pass>@<host>:<port>/<database_name>
  sqlite:///<database_file>

CONTACT

Jessica Severin <jessica.severin@gmail.com>

LICENSE

  * Software License Agreement (BSD License)
  * MappedQueryDB [MQdb] toolkit
  * copyright (c) 2006-2009 Jessica Severin
  * All rights reserved.
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *     * Redistributions of source code must retain the above copyright
  *       notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above copyright
  *       notice, this list of conditions and the following disclaimer in the
  *       documentation and/or other materials provided with the distribution.
  *     * Neither the name of Jessica Severin nor the
  *       names of its contributors may be used to endorse or promote products
  *       derived from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS BE LIABLE FOR ANY
  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

APPENDIX

The rest of the documentation details each of the object methods. Internal methods are usually preceded with a _

new

   Description: instance creation method
   Parameter  : a hash reference of options same as attribute methods
   Returntype : instance of this Class (subclass)
   Exceptions : none

new

   Description: instance creation method
   Returntype : instance of this Class (subclass)
   Exceptions : none

init

   Description: initialization method which subclasses can extend
   Returntype : $self
   Exceptions : subclass dependent

new_from_url

   Description: primary instance creation method
   Parameter  : a string in URL format
   Returntype : instance of MQdb::Database
   Examples   : my $db = MQdb::Database->new_from_url("mysql://<user>:<pass>@<host>:<port>/<database_name>");
                e.g. mysql://<host>:<port>/<database_name>
                e.g. mysql://<user>@<host>:<port>/<database_name>
                e.g. mysql://<host>/<database_name>
                e.g. sqlite:///<database_file> 
   my $class = shift;
   Exceptions : none

copy

   Description: makes a copy of the database configuration.
                New instance will have its own database connection 
   Returntype : instance of MQdb::Database

dbc

   Description: connects to database and returns a DBI connection
   Returntype : DBI database handle
   Exceptions : none

disconnect

   Description: disconnects handle from database, but retains object and 
                all information so that it can be reconnected again 
                at a later time.
   Returntype : none
   Exceptions : none

full_url

   Description: returns the URL of this database with user and password
   Returntype : string
   Exceptions : none

url

   Description: returns URL of this database but without user:password
                used for global referencing and federation systems
   Returntype : string
   Exceptions : none

xml

   Description: returns XML of this database but without user:password
                used for global referencing and federation systems
   Returntype : string
   Exceptions : none

execute_sql

   Description    : executes SQL statement with external parameters and placeholders
   Example        : $db->execute_sql("insert into table1(id, value) values(?,?)", $id, $value);
   Parameter[1]   : sql statement string
   Parameter[2..] : optional parameters for the SQL statement
   Returntype     : none
   Exceptions     : none

do_sql

   Description    : executes SQL statement with "do" and no external parameters
   Example        : $db->do_sql("insert into table1(id, value) values(null,'hello world');");
   Parameter      : sql statement string with no external parameters
   Returntype     : none
   Exceptions     : none

fetch_col_value

   Arg (1)    : $sql (string of SQL statement with place holders)
   Arg (2...) : optional parameters to map to the placehodlers within the SQL
   Example    : $value = $self->fetch_col_value($db, "select some_column from my_table where id=?", $id);
   Description: General purpose function to allow fetching of a single column from a single row.
   Returntype : scalar value
   Exceptions : none
   Caller     : within subclasses to easy development