make integer primary key compatible with oracle

changelog/5197.bugfix.rst

@@ -0,0 +1,4 @@
+Fixed incompatibility with Oracle, integer primary key is now a sequence and so can
+be used with Oracle.
+
+Added docs for setting up Oracle.

docs/api/tracker-stores.rst

@@ -70,6 +70,63 @@ SQLTrackerStore
     - ``login_db`` (default: ``None``): Alternative database name to which initially  connect, and create the database specified by `db` (PostgreSQL only)
     - ``query`` (default: ``None``): Dictionary of options to be passed to the dialect and/or the DBAPI upon connect
 
+
+:Supported Databases:
+    - PostgreSQL
+    - Oracle > 11.0
+    - SQLite
+
+
+:Oracle Configuration:
+
+
+      To use the SQLTrackerStore with Oracle, there are a few additional steps.
+      First, create a database ``tracker`` in your Oracle database and create a user with access to it.
+      Create a sequence in the database with the following command (where username is the user you created):
+
+      .. code-block:: sql
+
+          CREATE SEQUENCE username.events_seq;
+
+      Next you have to extend the Rasa Open Source image to include the necessary drivers and clients.
+
+      First download the Oracle Instant Client from `here <https://www.oracle.com/database/technologies/instant-client/linux-x86-64-downloads.html>`_,
+      rename it to ``oracle.rpm`` and store it in the directory from where you'll be building the docker image.
+
+      Copy this into a file called ``Dockerfile``:
+
+      .. code-block:: bash
+
+          FROM rasa/rasa:|version|-full
+          # Switch to root user to install packages
+          USER root
+          RUN apt-get update -qq \
+          && apt-get install -y --no-install-recommends \
+          alien \
+          libaio1 \
+          && apt-get clean \
+          && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+          # Copy in oracle instaclient
+          # https://www.oracle.com/database/technologies/instant-client/linux-x86-64-downloads.html
+          COPY oracle.rpm oracle.rpm
+          # Install the Python wrapper library for the Oracle drivers
+          RUN pip install cx-Oracle
+          # Install Oracle client libraries
+          RUN alien -i oracle.rpm
+          USER 1001
+
+      Then build the docker image:
+
+      .. code-block:: bash
+
+          docker build . -t rasa-oracle:latest
+
+      Now you can configure the tracker store in the ``endpoints.yml`` as described above,
+      and start the container. Read more about :ref:`running-rasa-with-docker`.
+
+
+
+
 RedisTrackerStore
 ~~~~~~~~~~~~~~~~~~
 

rasa/core/tracker_store.py

@@ -530,10 +530,11 @@ class SQLEvent(Base):
         """Represents an event in the SQL Tracker Store"""
 
         from sqlalchemy import Column, Integer, String, Float, Text
+        from rasa.core.utils import create_sequence
 
         __tablename__ = "events"
 
-        id = Column(Integer, primary_key=True)
+        id = Column(Integer, create_sequence(__tablename__), primary_key=True)
         sender_id = Column(String(255), nullable=False, index=True)
         type_name = Column(String(255), nullable=False)
         timestamp = Column(Float)

rasa/core/utils.py

@@ -35,6 +35,7 @@
 from rasa.utils.endpoints import EndpointConfig, read_endpoint_config
 from sanic import Sanic
 from sanic.views import CompositionView
+from sqlalchemy import Sequence
 
 logger = logging.getLogger(__name__)
 
@@ -538,3 +539,13 @@ def _log_and_get_default_number_of_workers():
         f"no `RedisLockStore` endpoint configuration has been found."
     )
     return _log_and_get_default_number_of_workers()
+
+
+def create_sequence(table_name: Text) -> Sequence:
+    """Creates a sequence object"""
+
+    from sqlalchemy.ext.declarative import declarative_base
+
+    sequence_name = f"{table_name}_seq"
+    Base = declarative_base()
+    return Sequence(sequence_name, metadata=Base.metadata, optional=True)