Changes

Explanation of the basics, underlying Gramps database. '''This is not intended to be a reference manual''', but an introductory programmer's guide to using the Gramps database access routines.

Separate [http://www.gramps-project.org/docs/ API Reference Documentation for version 45.0.x of Gramps] and as well as a simple [[Media:API.svg|UML (svg) for 4.1.x]] and [[Gramps Data Model]] overview are available.

*** '''DbReadBase''' - virtual and implementation-independent methods for reading data ([http://sourceforge.net/p/gramps/source/ci/master/tree/gramps/gen/db/base.py gen/db/base.py])*** '''Callback''' - callback and signal functions ([http://svn.code.sfsourceforge.net/p/gramps/codesource/ci/master/trunktree/gramps/gen/utils/callback.py gen/utils/callback.py])** '''UpdateCallback''' - callback functionality ([http://svn.code.sfsourceforge.net/p/gramps/codesource/ci/master/trunktree/gramps/gen/updatecallback.py gen/updatecallback.py])** '''DbTxn''' - class for managing Gramps transactions and the undo database ([http://sourceforge.net/p/gramps/source/ci/master/tree/gramps/gen/db//txn.py gen/db/txn.py])* '''DbDjangoDbGeneric''' - general read and write implementation to Django-based databases ([http://svn.code.sf.net/p/gramps/code/trunk/gramps/webapp/dbdjango.py webapp/dbdjango.py])implementations** '''DbWriteBase''' - virtual and implementation-independent methods for reading data ([http://sourceforge.net/p/gramps/source/ci/master/tree/gramps/gen/db//base.py gen/db/base.py])

The DbBsddb interface defines a hierarchical database (non-relational) written in [http://www.jcea.es/programacion/pybsddb.htm PyBSDDB]. There is no such thing as a database schema, and the meaning of the data is defined in the Python classes above. The data is stored as pickled tuples and unserialized into the [[Using_database_API#Primary_Objects|primary data types (below)]]. === DB-API ===

The DbDjango interface defines the By default, Gramps data in terms of ''models'' and ''relations'' from the [http://wwwDB-API uses sqlite.djangoproject.com/ Django project]. The database backend However, you can be any implementation that supports Django, including such popular SQL implementations as sqlite, MySQL, Postgresqlalso configure DB-API to use mysql, and Oracle. The data is retrieved from the SQL fieldspostgresql, serialized and then unserialized into the primary data types (below)perhaps others.

For more details on the To be compatible with BSDDB, DB-API stores Gramps Django projectdata in an identical manner (pickled tuples). However, to allow for fast access, DB-API also stores "flat" data (such as strings and integers) in secondary SQL fields. These are indexed so that data can be selected without having to traverse, unpickle, see [[GEPS 013: Gramps Webapp]]initialize objects, and compare properties.

The handle should not be visible to the end user, and should not be included in reports or displayed on screen. Instead, the GRAMPS Gramps ID value should be used for this purpose. The GRAMPS Gramps ID is a user defined value for each object, but is not used internally to the database. This allows the user to change the GRAMPS Gramps ID without affecting the database.

A full list of the signals that are emitted from the database can be found at the top of the <tt>[https://gramps-project.org/docs/gen/gen_db.html#module-gramps.gen.db.base GrampsDbBase]</tt> class in the <tt>GrampsDbBase[https://github.com/gramps-project/gramps/blob/master/gramps/gen/db/base.py gramps/gen/db/base.py]</tt> module.