Update documentation for SQL event broker.

docs/api/event-brokers.rst

@@ -27,7 +27,11 @@ tracker looks like this:
 The ``event`` field takes the event's ``type_name`` (for more on event
 types, check out the :ref:`events` docs).
 
-Rasa enables two possible brokers producers: Pika Event Broker and Kafka Event Broker.
+Rasa enables three possible broker types:
+
+- `Pika Event Broker`_
+- `Kafka Event Broker`_
+- `SQL Event Broker`_
 
 Pika Event Broker
 -----------------
@@ -108,7 +112,7 @@ example:
 Kafka Event Broker
 ------------------
 
-It is possible to use `Kafka <https://kafka.apache.org/>`_ as main broker to you events. In this example
+It is possible to use `Kafka <https://kafka.apache.org/>`_ as main broker for your events. In this example
 we are going to use the `python-kafka <https://kafka-python.readthedocs.io/en/master/usage.html>`_
 library, a Kafka client written in Python.
 
@@ -231,3 +235,51 @@ according to the security protocol being used. The following implementation show
 
     for message in consumer:
         print(message.value)
+
+SQL Event Broker
+-----------------
+
+It is possible to use  an SQL database as an event broker. Connections to databases are established using
+`SQLAlchemy <https://www.sqlalchemy.org/>`_, a Python library which can interact with many
+different types of SQL databases, such as `SQLite <https://sqlite.org/index.html>`_,
+`PostgreSQL <https://www.postgresql.org/>`_ and more. The default Rasa installation allows connections to SQLite
+and PostgreSQL databases, to see other options, please see the
+`SQLAlchemy documentation on SQL dialects <https://docs.sqlalchemy.org/en/13/dialects/index.html>`_.
+
+
+Adding a SQL Event Broker Using the Endpoint Configuration
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+You can use an endpoint configuration file to instruct Rasa to stream
+all events to your SQL event broker. To do so, add a ``event_broker`` section to your
+endpoint configuration, e.g. ``endpoints.yml``. For example, a valid SQLite configuration
+could look like the following:
+
+.. code-block:: yml
+
+    event_broker:
+      type: SQL
+      dialect: sqlite
+      db: events.db
+
+PostgreSQL databases can be used as well:
+
+.. code-block:: yml
+
+    event_broker:
+      type: SQL
+      host: 127.0.0.1
+      port: 5432
+      dialect: postgresql
+      username: myuser
+      password: mypassword
+      db: mydatabse
+
+Then, instruct Rasa to use the endpoint configuration and SQL producer by adding
+``--endpoints <path to your endpoint configuration`` as following example:
+
+.. code-block:: shell
+
+    rasa run -m models --endpoints endpoints.yml
+
+Rasa will then create a table called ``events``, where all events will be added.

rasa/core/broker.py

@@ -17,7 +17,7 @@ def from_endpoint_config(
         return None
     elif broker_config.type == "pika" or broker_config.type is None:
         return PikaProducer.from_endpoint_config(broker_config)
-    elif broker_config.type == "sql":
+    elif broker_config.type.lower() == "sql":
         return SQLProducer.from_endpoint_config(broker_config)
     elif broker_config.type == "file":
         return FileProducer.from_endpoint_config(broker_config)