This is a work in progress. There's also an article about sumo_db. This articles might be a little outdated by now, but can still provide some basic information on how to get started.
sumo_db aims to ease db access for erlang applications. It offers a very simple persistance layer capable of interacting with different db's, while offering a consistent api to your code.
If you find any bugs or have a problem while using this library, please open an issue in this repo (or a pull request :)).
-
sumo_db gives you a standard way to define your db schema, regardless of the db implementation (mongo, mysql, redis, elasticsearch, etc.).
-
Your entities encapsulate behavior in code (i.e. functions in a module) and state in a
sumo:doc()
implementation. -
sumo
is the main module. It translates to and from sumo internal records into your own state. -
Each store is managed by a worker pool of processes, each one using a module that implements
sumo_store
and calls the actual db driver (e.g:sumo_store_mnesia
). -
Some native domain events are supported, that are dispatched through a
gen_event:notify/2
automatically when an entity is created, updated, deleted. Also when a schema is created and when all entities of a given type are deleted. Events are described in this article. -
Full conditional logic support when using
find_by/2
anddelete_by/2
function. You can find more information about the syntax of this conditional logic operators here. -
Support for sorting (
asc
ordesc
) based on multiple fields unsingfind_by/5
andfind_all/4
functions. For example this[{age, desc}, {name, asc}]]
will sort descendently byage
and ascendently byname
. -
Support for docs/models validations through
sumo_changeset
(check out the Changeset section).
These three concepts have a specific meaning in the context of sumo_db.
-
Backend: establishes and holds a single Database instance connection.
-
Store: implements the specific operations that modify the contents of the backend and retrieves the information it holds.
-
Repository: the application that uses
sumo_db
should implement one repository for each entity that's defined in it. The repository is the module that bridges the model and the store.
- Mnesia β built-in with
sumo
- Riak
- PostgreSQL
- MySQL
- MongoDB
- ElasticSearch
To implement an adapter, you must implement two specific behaviours:
- sumo_backend β DB connection
- sumo_store β implements the Sumo API
You can check the implemented adapters mentioned above in order to have a better idea about how to build a custom adapter from scratch.
Sumo dispatches events when things happen. An Event has this structure:
{EventId, Model, Event, Args}
EventId
is areference()
which identifies the eventModel
is the model where the event happend, for example, if we are creating a new entitiy in the modelpeople
the value ofModel
would bepeople
.Event
is the type of the event.Args
extra data sent.
Supported types of events:
pre_persisted
just before persisting some entity. This event has the entity we want to persist asArgs
. It is dispatched on this function:sumo:persist/2
persisted
just after persisting some entity. This event has the persisted entity asArgs
. This Event has the sameEventId
as itspre_persisted
event. It is dispatched on this function:sumo:persist/2
pre_delete_all
just before deleting all entities for a model. This event has noArgs
. It is dispatched on this function:sumo:delete_all/1
deleted_all
just after deleting all entities for a model. This event has noArgs
. This Event has the sameEventId
as itspre_delete_all
event. It is dispatched on this function:sumo:delete_all/1
pre_deleted
just before deleting an entity. This event has the entity id asArgs
. It is dispatched on this function:sumo:delete/2
deleted
just after deleting an entity. This event has the entity id asArgs
. This Event has the sameEventId
as itspre_deleted
event. It is dispatched on this function:sumo:delete/2
pre_deleted_total
just before deleting by some delete conditions. This event has the sumo conditions asArgs
. It is dispatched on this function:sumo:delete_by/2
deleted_total
just after deleting by some delete conditions. This event has a list with the number of entities deleted and the delete conditions asArgs
. This Event has the sameEventId
as itspre_deleted_total
event. It is dispatched on this function:sumo:delete_by/2
pre_schema_created
just before creating a sumo schema. This event has noArgs
. It is dispatched on this function:sumo:create_schema/2
schema_created
just after creating a sumo schema. This event has noArgs
. This Event has the sameEventId
as itspre_schema_created
event. It is dispatched on this function:sumo:create_schema/2
Sumo requires users to add their own gen_event
's in order to handle those events. In order to add them Users have to configure sumo properly. In the config
file we can add them like this under sumo_db
configuration:
{events, [
{'_', sumo_test_people_events_manager},
{people, sumo_test_people_events_manager}
]}
Sumo allows us to add a gen_event
to one type of model (i.e. people
) or for all ('_'
).
This feature is inspired by Elixir Ecto.Changeset, and the module that implements this feature is sumo_changeset.
NOTE: This example uses FancyFlow in order to pipe changeset functions in a nicer way.
%% suppose you have a model/doc `person`, and that module provides a function
%% to encapsulate model/doc creation
Person = person:new(<<"John">>, <<"Doe">>),
%% create the set of params/changes
Params = #{age => 33, id => 1, <<"last_name">> => <<"other">>},
%% run the changeset
Changeset = [pipe](people,
sumo_changeset:cast(_, Person, Params, [id, first_name, last_name, age, status]),
sumo_changeset:validate_required(_, [id, last_name, status]),
sumo_changeset:validate_inclusion(_, status, [<<"active">>, <<"blocked">>]),
sumo_changeset:validate_number(_, age, [{less_than_or_equal_to, 18}]),
sumo_changeset:validate_length(_, last_name, [{min, 3}]),
sumo_changeset:validate_format(_, last_name, <<"^[a-zA-Z]">>)),
See: examples/blog for a full example. To run it, while being in the top level directory:
make all blog
See: examples/custom_store for creating your own Store. To run it, follow the instructions in this README
$ rebar3 dialyzer
$ rebar3 ct
All notable changes to this project will be documented in the CHANGELOG.md.
We want to thank all of our contributors for their hard work :muscle:.