Permissions

migrations/0001_initial.up.sql

@@ -32,5 +32,6 @@ CREATE TABLE
         permission_id SERIAL PRIMARY KEY,
         user_id INT REFERENCES users (user_id) ON DELETE CASCADE NOT NULL,
         folder_id UUID REFERENCES folders (folder_id) ON DELETE CASCADE,
-        permission_type permission NOT NULL
+        permission_type permission NOT NULL,
+        UNIQUE (user_id, folder_id)
     );