MQdb::Database(3pm)					User Contributed Perl Documentation				       MQdb::Database(3pm)

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

perl v5.10.0							    2009-05-30						       MQdb::Database(3pm)