Document database migrations

Closes #390

1 files changed, 16 insertions, 1 deletions

diff --git a/docs/contributing.rst b/docs/contributing.rst
index 1944d67..bcb3f16 100644
--- a/docs/contributing.rst
+++ b/docs/contributing.rst
@@ -39,7 +39,6 @@ Accessing dev server
 In any case, you can point your browser at `http://localhost:5000 <http://localhost:5000>`_.
 It's as simple as that!
 
-
 Updating
 --------
 
@@ -47,6 +46,22 @@ In case you want to update to newer versions (from git), you can just run the "u
 
   make update
 
+Create database migrations
+--------------------------
+
+In case you need to modify the database schema, first update the models in ihatemoney/models.py.
+Then run the following command to create a new database revision file::
+
+  make create-database-revision
+
+If your changes are simple enough, the generated script will be populated with
+the necessary migrations steps. You can edit the generated script. eg: to add data migrations.
+
+For complex migrations, it is recommended to start from an empty revision file which can be created
+with the following command::
+
+  make create-empty-database-revision
+
 Useful settings
 ----------------