raoul/openlp
1
0
Fork 0
forked from openlp/openlp
Code Issues Pull Requests Projects Releases Wiki Activity

- Implemented a seamless database upgrade system.

Browse Source 
- Added the first upgrade as a demonstration.
- Added database version check so that newer version databases are not loaded.

bzr-revno: 1721
This commit is contained in:
Raoul Snyman 2011-08-26 13:39:32 +02:00
commit 2c0df18f35
6 changed files with 181 additions and 37 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

84
openlp/core/lib/db.py
View File

@ -31,11 +31,13 @@ import logging
import os
from PyQt4 import QtCore
from sqlalchemy import create_engine, MetaData
from sqlalchemy.exc import InvalidRequestError
from sqlalchemy.orm import scoped_session, sessionmaker
from sqlalchemy import Table, MetaData, Column, types, create_engine
from sqlalchemy.exc import SQLAlchemyError, InvalidRequestError, DBAPIError
from sqlalchemy.orm import scoped_session, sessionmaker, mapper
from sqlalchemy.pool import NullPool
from openlp.core.lib import translate
from openlp.core.lib.ui import critical_error_message_box
from openlp.core.utils import AppLocation, delete_file
log = logging.getLogger(__name__)
@ -59,6 +61,48 @@ def init_db(url, auto_flush=True, auto_commit=False):
autocommit=auto_commit, bind=engine))
return session, metadata
def upgrade_db(url, upgrade):
"""
Upgrade a database.
``url``
The url of the database to upgrade.
``upgrade``
The python module that contains the upgrade instructions.
"""
session, metadata = init_db(url)
tables = upgrade.upgrade_setup(metadata)
metadata_table = Table(u'metadata', metadata,
Column(u'key', types.Unicode(64), primary_key=True),
Column(u'value', types.UnicodeText(), default=None)
)
metadata_table.create(checkfirst=True)
mapper(Metadata, metadata_table)
version_meta = session.query(Metadata).get(u'version')
if version_meta is None:
version_meta = Metadata.populate(key=u'version', value=u'0')
version = 0
else:
version = int(version_meta.value)
if version > upgrade.__version__:
return version, upgrade.__version__
version += 1
while hasattr(upgrade, u'upgrade_%d' % version):
log.debug(u'Running upgrade_%d', version)
try:
getattr(upgrade, u'upgrade_%d' % version)(session, metadata, tables)
version_meta.value = unicode(version)
except SQLAlchemyError, DBAPIError:
log.exception(u'Could not run database upgrade script "upgrade_%s"'\
', upgrade process has been halted.', version)
break
version += 1
session.add(version_meta)
session.commit()
return int(version_meta.value), upgrade.__version__
def delete_database(plugin_name, db_file_name=None):
"""
Remove a database file from the system.
@ -79,6 +123,7 @@ def delete_database(plugin_name, db_file_name=None):
AppLocation.get_section_data_path(plugin_name), plugin_name)
return delete_file(db_file_path)
class BaseModel(object):
"""
BaseModel provides a base object with a set of generic functions
@ -94,11 +139,19 @@ class BaseModel(object):
return instance
class Metadata(BaseModel):
"""
Provides a class for the metadata table.
"""
pass
class Manager(object):
"""
Provide generic object persistence management
"""
def __init__(self, plugin_name, init_schema, db_file_name=None):
def __init__(self, plugin_name, init_schema, db_file_name=None,
upgrade_mod=None):
"""
Runs the initialisation process that includes creating the connection
to the database and the tables if they don't exist.
@ -109,6 +162,9 @@ class Manager(object):
``init_schema``
The init_schema function for this database
``upgrade_schema``
The upgrade_schema function for this database
``db_file_name``
The file name to use for this database. Defaults to None resulting
in the plugin_name being used.
@ -134,7 +190,27 @@ class Manager(object):
unicode(settings.value(u'db hostname').toString()),
unicode(settings.value(u'db database').toString()))
settings.endGroup()
if upgrade_mod:
db_ver, up_ver = upgrade_db(self.db_url, upgrade_mod)
if db_ver > up_ver:
critical_error_message_box(
translate('OpenLP.Manager', 'Database Error'),
unicode(translate('OpenLP.Manager', 'The database being '
'loaded was created in a more recent version of '
'OpenLP. The database is version %d, while OpenLP '
'expects version %d. The database will not be loaded.'
'\n\nDatabase: %s')) % \
(db_ver, up_ver, self.db_url)
)
return
try:
self.session = init_schema(self.db_url)
except:
critical_error_message_box(
translate('OpenLP.Manager', 'Database Error'),
unicode(translate('OpenLP.Manager', 'OpenLP cannot load your '
'database.\n\nDatabase: %s')) % self.db_url
)
def save_object(self, object_instance, commit=True):
"""

41
openlp/plugins/songs/lib/db.py
View File

@ -70,7 +70,6 @@ class Topic(BaseModel):
"""
pass
def init_schema(url):
"""
Setup the songs database connection and initialise the database schema.
@ -111,10 +110,6 @@ def init_schema(url):
* file_name
* type
**media_files_songs Table**
* media_file_id
* song_id
**song_books Table**
The *song_books* table holds a list of books that a congregation gets
their songs from, or old hymnals now no longer used. This table has the
@ -162,7 +157,7 @@ def init_schema(url):
# Definition of the "authors" table
authors_table = Table(u'authors', metadata,
Column(u'id', types.Integer, primary_key=True),
Column(u'id', types.Integer(), primary_key=True),
Column(u'first_name', types.Unicode(128)),
Column(u'last_name', types.Unicode(128)),
Column(u'display_name', types.Unicode(255), index=True, nullable=False)
@ -170,22 +165,25 @@ def init_schema(url):
# Definition of the "media_files" table
media_files_table = Table(u'media_files', metadata,
Column(u'id', types.Integer, primary_key=True),
Column(u'id', types.Integer(), primary_key=True),
Column(u'song_id', types.Integer(), ForeignKey(u'songs.id'),
default=None),
Column(u'file_name', types.Unicode(255), nullable=False),
Column(u'type', types.Unicode(64), nullable=False, default=u'audio')
Column(u'type', types.Unicode(64), nullable=False, default=u'audio'),
Column(u'weight', types.Integer(), default=0)
)
# Definition of the "song_books" table
song_books_table = Table(u'song_books', metadata,
Column(u'id', types.Integer, primary_key=True),
Column(u'id', types.Integer(), primary_key=True),
Column(u'name', types.Unicode(128), nullable=False),
Column(u'publisher', types.Unicode(128))
)
# Definition of the "songs" table
songs_table = Table(u'songs', metadata,
Column(u'id', types.Integer, primary_key=True),
Column(u'song_book_id', types.Integer,
Column(u'id', types.Integer(), primary_key=True),
Column(u'song_book_id', types.Integer(),
ForeignKey(u'song_books.id'), default=None),
Column(u'title', types.Unicode(255), nullable=False),
Column(u'alternate_title', types.Unicode(255)),
@ -202,31 +200,23 @@ def init_schema(url):
# Definition of the "topics" table
topics_table = Table(u'topics', metadata,
Column(u'id', types.Integer, primary_key=True),
Column(u'id', types.Integer(), primary_key=True),
Column(u'name', types.Unicode(128), index=True, nullable=False)
)
# Definition of the "authors_songs" table
authors_songs_table = Table(u'authors_songs', metadata,
Column(u'author_id', types.Integer,
Column(u'author_id', types.Integer(),
ForeignKey(u'authors.id'), primary_key=True),
Column(u'song_id', types.Integer,
ForeignKey(u'songs.id'), primary_key=True)
)
# Definition of the "media_files_songs" table
media_files_songs_table = Table(u'media_files_songs', metadata,
Column(u'media_file_id', types.Integer,
ForeignKey(u'media_files.id'), primary_key=True),
Column(u'song_id', types.Integer,
Column(u'song_id', types.Integer(),
ForeignKey(u'songs.id'), primary_key=True)
)
# Definition of the "songs_topics" table
songs_topics_table = Table(u'songs_topics', metadata,
Column(u'song_id', types.Integer,
Column(u'song_id', types.Integer(),
ForeignKey(u'songs.id'), primary_key=True),
Column(u'topic_id', types.Integer,
Column(u'topic_id', types.Integer(),
ForeignKey(u'topics.id'), primary_key=True)
)
@ -238,8 +228,7 @@ def init_schema(url):
'authors': relation(Author, backref='songs',
secondary=authors_songs_table, lazy=False),
'book': relation(Book, backref='songs'),
'media_files': relation(MediaFile, backref='songs',
secondary=media_files_songs_table),
'media_files': relation(MediaFile, backref='songs'),
'topics': relation(Topic, backref='songs',
secondary=songs_topics_table)
})

77
openlp/plugins/songs/lib/upgrade.py Normal file
View File

@ -0,0 +1,77 @@
# -*- coding: utf-8 -*-
# vim: autoindent shiftwidth=4 expandtab textwidth=80 tabstop=4 softtabstop=4
###############################################################################
# OpenLP - Open Source Lyrics Projection #
# --------------------------------------------------------------------------- #
# Copyright (c) 2008-2011 Raoul Snyman #
# Portions copyright (c) 2008-2011 Tim Bentley, Gerald Britton, Jonathan #
# Corwin, Michael Gorven, Scott Guerrieri, Matthias Hub, Meinert Jordan, #
# Armin Köhler, Joshua Miller, Stevan Pettit, Andreas Preikschat, Mattias #
# Põldaru, Christian Richter, Philip Ridout, Simon Scudder, Jeffrey Smith, #
# Maikel Stuivenberg, Martin Thompson, Jon Tibble, Frode Woldsund #
# --------------------------------------------------------------------------- #
# This program is free software; you can redistribute it and/or modify it #
# under the terms of the GNU General Public License as published by the Free #
# Software Foundation; version 2 of the License. #
# #
# This program is distributed in the hope that it will be useful, but WITHOUT #
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or #
# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for #
# more details. #
# #
# You should have received a copy of the GNU General Public License along #
# with this program; if not, write to the Free Software Foundation, Inc., 59 #
# Temple Place, Suite 330, Boston, MA 02111-1307 USA #
###############################################################################
"""
The :mod:`upgrade` module provides a way for the database and schema that is the backend for
the Songs plugin
"""
from sqlalchemy import Column, ForeignKey, Table, types
from migrate import changeset
from migrate.changeset.constraint import ForeignKeyConstraint
__version__ = 1
def upgrade_setup(metadata):
"""
Set up the latest revision all tables, with reflection, needed for the
upgrade process. If you want to drop a table, you need to remove it from
here, and add it to your upgrade function.
"""
tables = {
u'authors': Table(u'authors', metadata, autoload=True),
u'media_files': Table(u'media_files', metadata, autoload=True),
u'song_books': Table(u'song_books', metadata, autoload=True),
u'songs': Table(u'songs', metadata, autoload=True),
u'topics': Table(u'topics', metadata, autoload=True),
u'authors_songs': Table(u'authors_songs', metadata, autoload=True),
u'songs_topics': Table(u'songs_topics', metadata, autoload=True)
}
return tables
def upgrade_1(session, metadata, tables):
"""
Version 1 upgrade.
This upgrade removes the many-to-many relationship between songs and
media_files and replaces it with a one-to-many, which is far more
representative of the real relationship between the two entities.
In order to facilitate this one-to-many relationship, a song_id column is
added to the media_files table, and a weight column so that the media
files can be ordered.
"""
Table(u'media_files_songs', metadata, autoload=True).drop(checkfirst=True)
Column(u'song_id', types.Integer(), default=None)\
.create(table=tables[u'media_files'], populate_default=True)
Column(u'weight', types.Integer(), default=0)\
.create(table=tables[u'media_files'], populate_default=True)
if metadata.bind.url.get_dialect().name != 'sqlite':
# SQLite doesn't support ALTER TABLE ADD CONSTRAINT
ForeignKeyConstraint([u'song_id'], [u'songs.id'],
table=tables[u'media_files']).create()

5
openlp/plugins/songs/songsplugin.py
View File

@ -36,7 +36,8 @@ from openlp.core.lib import Plugin, StringContent, build_icon, translate, \
from openlp.core.lib.db import Manager
from openlp.core.lib.ui import UiStrings, base_action, icon_action
from openlp.core.utils.actions import ActionList
from openlp.plugins.songs.lib import clean_song, SongMediaItem, SongsTab
from openlp.plugins.songs.lib import clean_song, upgrade, SongMediaItem, \
SongsTab
from openlp.plugins.songs.lib.db import init_schema, Song
from openlp.plugins.songs.lib.importer import SongFormat
from openlp.plugins.songs.lib.olpimport import OpenLPSongImport
@ -58,8 +59,8 @@ class SongsPlugin(Plugin):
Create and set up the Songs plugin.
"""
Plugin.__init__(self, u'songs', plugin_helpers, SongMediaItem, SongsTab)
self.manager = Manager(u'songs', init_schema, upgrade_mod=upgrade)
self.weight = -10
self.manager = Manager(u'songs', init_schema)
self.icon_path = u':/plugins/plugin_songs.png'
self.icon = build_icon(self.icon_path)

2
resources/debian/debian/control
View File

@ -11,7 +11,7 @@ Package: openlp
Architecture: all
Depends: ${shlibs:Depends}, ${misc:Depends}, ${python:Depends}, python-qt4,
python-qt4-phonon, python-sqlalchemy, python-chardet, python-beautifulsoup,
python-lxml, python-sqlite, python-enchant
python-lxml, python-sqlite, python-enchant, python-migrate
Conflicts: python-openlp
Description: Church lyrics projection application
OpenLP is free church presentation software, or lyrics projection software,

1
scripts/check_dependencies.py
View File

@ -72,6 +72,7 @@ MODULES = [
'enchant',
'BeautifulSoup',
'mako',
'migrate',
]