Temporal tables for Sequelize

(aka "Historical records")

What is it?

Temporal tables maintain historical versions of data. Modifying operations (UPDATE, DELETE) on these tables don't cause permanent changes to entries, but create new versions of them. Hence this might be used to:

• log changes (security/auditing)
• undo functionalities
• track interactions (customer support)

Under the hood a history table with the same structure, but without constraints is created.

The normal singular/plural naming scheme in Sequelize is used:

• model name: modelName + History
• table name: modelName + Histories

Installation

npm install sequelize-temporal

How to use

1) Import sequelize-temporal

var Sequelize = require('sequelize');
var Temporal = require('sequelize-temporal');

Create a sequelize instance and your models, e.g.

var sequelize = new Sequelize('', '', '', {
	dialect: 'sqlite',
	storage: __dirname + '/.test.sqlite'
});

2) Add the temporal feature to your models

var User = Temporal(sequelize.define('User'), sequelize);

The output of temporal is its input model, so assigning it's output to your Model is not necessary, hence it's just the lazy version of:

var User = sequelize.define('User', {.types.}, {.options.}); // Sequelize Docu
Temporal(User, sequelize);

Options

The default syntax for Temporal is:

Temporal(model, sequelizeInstance, options)

whereas the options are listed here (with default value).

{
    /**
     * Runs the insert within the sequelize hook chain, disable for increased performance without warranties
     */
    blocking: true,
    /**
     * By default sequelize-temporal persist only changes, and saves the previous state in the history table.
     * The "full" option saves all transactions into the temporal database (i.e. this includes the latest state.)
     * This allows to only query the hostory table to get the full history of an entity.
     */
    full: false,
    /**
     * Whether to skip inserting an History line if the update() call is silent.
     */
    skipIfSilent: false,
    /**
     * This library will sometimes reload() an updated entity because it misses a few attributes. In order to minimize
     * the number of extra SQL queries, an heuristic is applied to perform the reload() only if necessary. This mainly
     * boils down to "is this attribute <x> missing ?".
     * The `reloadIgnoredAttributes` can be used to ignore certain attributes from this check.
     */
    reloadIgnoredAttributes: ['deletedAt']
}

Details

@See: https://wiki.postgresql.org/wiki/SQL2011Temporal

History table

History table stores historical versions of rows, which are inserted by triggers on every modifying operation executed on current table. It has the same structure and indexes as current table, but it doesn’t have any constraints. History tables are insert only and creator should prevent other users from executing updates or deletes by correct user rights settings. Otherwise the history can be violated.

Hooks

Triggers for storing old versions of rows to history table are inspired by referential integrity triggers. They are fired for each row before UPDATE and DELETE (within the same transaction)

Notes

If you only use Postgres, you might want to have a look at the Temporal Table extension.

License

The MIT License (MIT)

Copyright (c) 2015 BonaVal

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.