And then call C<< $schema->journal_schema_deploy >> to create all the tables
necessary for the journal, in your database.
-Optionally set where the journal is stored, and associate a user ID with
-each changeset.
+Optionally set where the journal is stored:
__PACKAGE__->journal_connection(['dbi:SQLite:t/var/Audit.db']);
- __PACKAGE__->journal_user(['My::Schema::User', {'foreign.userid' => 'self.user_id'}]);
-
- #######
+Later on, in your application, wrap operations in transactions, and optionally
+associate a user with the changeset:
$schema->changeset_user($user->id);
my $new_artist = $schema->txn_do( sub {
return $schema->resultset('Artist')->create({ name => 'Fred' });
});
-
=head1 DESCRIPTION
The purpose of this L<DBIx::Class> component module is to create an
audit-trail for all changes made to the data in your database (via a
-DBIx::Class schema). It creates changesets and assigns each
-create/update/delete operation an id. The creation and deletion date
-of each row is stored, as well as the previous contents of any row
-that gets changed.
+DBIx::Class schema). It creates I<changesets> and assigns each
+create/update/delete operation an I<id>. The creation and deletion date of
+each row is stored, as well as the historical contents of any row that gets
+changed.
All queries which need auditing must be called using
-L<DBIx::Class::Schema/txn_do>, which is used to create changesets for
-each transaction.
+L<DBIx::Class::Schema/txn_do>, which is used to create changesets for each
+transaction.
-To track who did which changes, the user_id (an integer) of the
-current user can be set, a session_id can also be set, both are
-optional.
+To track who did which changes, the C<user_id> (an integer) of the current
+user can be set, and a C<session_id> can also be set; both are optional.
-To access the auditing schema to look at the auditdata or revert a
-change, use C<< $schema->_journal_schema >>.
+To access the auditing schema to look at the auditdata or revert a change, use
+C<< $schema->_journal_schema >>.
-=head2 TABLES
+=head1 DEPLOYMENT
-The journal schema contains a number of tables.
+Currently the module expects to be deployed alongside a new database schema,
+and track all changes from first entry. Do do that you need to add some tables
+for the journal, and you can configure which tables have their operations
+journalled by the module.
-=over
+Connect to your schema and deploy the journal tables as below. The module
+automatically scans your schema and sets up storage for journal entries.
-=item ChangeSet
+ My::Schema->journal_sources([qw/ table1 table2 /]);
+
+ $schema = My::Schema->connect(...);
+ $schema->journal_schema_deploy;
-Each changeset row has an auto-incremented ID, optional user_id and
-session_id, and a set_date which defaults to the current datetime.
+Note that if you are retrofitting journalling to an existing database, then as
+well as creating the journal you will need to populate it with a history so
+that when rows are deleted they can be mapped back to a (fake) creation.
-A ChangeSet has_many Changes.
+=head1 TABLES
+
+The journal schema contains a number of tables. These track row creation,
+update and deletion, and also are aware of multiple operations taking place
+within one transaction.
+
+=over 4
+
+=item ChangeSet
+
+Each changeset row has an auto-incremented C<ID>, optional C<user_id> and
+C<session_id>, and a C<set_date> which defaults to the current datetime. This
+is the authoritative log of one discrete change to your database, which may
+possible consist of a number of ChangeLog operations within a single
+transaction.
=item ChangeLog
-Each change/operation done in the transaction is recorded as a row in
-the ChangeLog table. It contains an auto-incrementing ID, the
-changeset_id and an order column for the ordering of each change in
-the changeset.
+Each operation done within the transaction is recorded as a row in the
+ChangeLog table. It contains an auto-incrementing C<ID>, the C<changeset_id>
+and an C<order> column to establish the order in which changes took place.
=item AuditLog
-For every table in the original database that is to be audited, an
-AuditLog table is created. Each auditlog row has an id which will
-contain the primary key of the table it is associated with. (NB:
-currently only supports integer-based single column PKs). The
-create_id and delete_id fields contain the IDs of the Changes that
-created or deleted this row.
+For every table in the original database that is to be audited, an AuditLog
+table is created. When a row appears in the original database a corresponding
+row is added here with a ChangeLog ID in the C<create_id> column, and when
+that original row is deleted the AuditLog is updated to add another ChangeLog
+ID this time into the C<delete_id> column. A third id column contains the
+primary key of the original row, so you can find it in the AuditHistory.
+
+Note that currently only integer-based single column primary keys are
+supported in your original database tables.
=item AuditHistory
-For every table in the original database to be audited, an
-AuditHistory table is created. Each row has a change_id field
-containing the ID of the ChangeLog row. The other fields correspond to
-all the fields from the original table. Each time a column value in
-the original table is changed, the entire row contents before the
-change are added as a new row in this table.
+For every table in the original database to be audited, an AuditHistory table
+is created. This is where the actual field data from your original table rows
+are stored on creation and on each update.
+
+Each row in the AuditHistory has a C<change_id> field containing the ID of the
+ChangeLog row. The other fields correspond to all the fields from the original
+table (with any constraints removed). Each time a column value in the original
+table is changed, the entire row contents after the change are added as a new
+row in this table.
=back
-=head2 METHODS
+=head1 CLASS METHODS
+
+Call these in your Schema Class such as the C<My::Schema> package file, as in
+the SYNOPSIS, above.
-=over
+=over 4
=item journal_connection \@connect_info
-Set the connection information for the database to save your audit
-information to.
+Set the connection information for the database to save your audit information
+to.
Leaving this blank assumes you want to store the audit data into your current
database. The storage object will be shared by the regular schema and the
=item journal_sources \@source_names
-Set a list of source names you would like to audit, if unset, all
-sources are used.
+Set a list of source names you would like to audit. If unset, all sources are
+used.
-NOTE: Currently only sources with a single-column PK are supported, so
-use this method if you have sources with multi-column PKs.
+NOTE: Currently only sources with a single-column integer PK are supported, so
+use this method if you have sources which don't comply with that limitation.
=item journal_storage_type $type
=item journal_user \@rel
-The user_id column in the L</ChangeSet> will be linked to your user id
-with a belongs_to relation, if this is set with the appropriate
-arguments.
+The user_id column in the L</ChangeSet> will be linked to your user id with a
+C<belongs_to> relation, if this is set with the appropriate arguments. For
+example:
+
+ __PACKAGE__->journal_user(['My::Schema::User', {'foreign.userid' => 'self.user_id'}]);
+
+=back
+
+=head1 OBJECT METHODS
+
+Once you have a connection to your database, call these methods to manage the
+journalling.
+
+=over 4
=item journal_schema_deploy
-Will use L<DBIx::Class::Schema/deploy> to set up the tables for
-journalling in your schema. Use this method to set up your journal.
+Will use L<DBIx::Class::Schema/deploy> to set up the tables for journalling in
+your schema. Use this method to set up your journal.
+
+Note that if you are retrofitting journalling to an existing database, then as
+well as creating the journal you will need to populate it with a history so
+that when rows are deleted they can be mapped back to a (fake) creation.
=item journal_deploy_on_connect $bool
=item changeset_user $user_id
-Set the user_id for the following changeset(s). This must be an integer.
+Set the C<user_id> for the following changeset(s). This must be an integer.
=item changeset_session $session_id
-Set the session_id for the following changeset(s). This must be an integer.
+Set the C<session_id> for the following changeset(s). This must be an integer.
=item deploy
-Overloaded L<DBIx::Class::Schema/deploy> which will deploy your primary
+Overloaded L<DBIx::Class::Schema/deploy> which will deploy your original
database schema and following that will deploy the journal schema.
=item txn_do $code_ref, @args
-Overloaded L<DBIx::Class::Schema/txn_do>, this must be used to start a
-new changeset to cover a group of changes. Each subsequent change to
-an audited table will use the changeset_id created in the most recent
-txn_do call.
+Overloaded L<DBIx::Class::Schema/txn_do>, this must be used to start a new
+ChangeSet to cover a group of changes. Each subsequent change to an audited
+table will use the C<changeset_id> created in the most recent C<txn_do> call.
Currently nested C<txn_do> calls cause a single ChangeSet object to be created.
=head1 SEE ALSO
+=over 4
+
+=item *
+
L<DBIx::Class> - You'll need it to use this.
-=head1 NOTES
+=back
-Only single-column integer primary key'd tables are supported for auditing so far.
+=head1 LIMITATIONS
+
+=over 4
+
+=item *
+
+Only single-column integer primary key'd tables are supported for auditing.
+
+=item *
Updates made via L<DBIx::Class::ResultSet/update> are not yet supported.
+=item *
+
No API for viewing or restoring changes yet.
-Patches for the above welcome ;)
+=back
+
+Patches for the above are welcome ;-)
=head1 AUTHOR
projects / dbsrgits/DBIx-Class-Journal.git / commitdiff