postgres migration for updating the RULE to be v14 compatible (#1668)

* postgres migration for updating the RULE to be v14 compatible

* update the problematic rule in place also

* Add note about applying new migration for pg 14

---------

Co-authored-by: Christopher Small <[email protected]>

docs/migrations.md

@@ -8,12 +8,12 @@ But if we update the database schema after your initial provisioning of your ser
 
 - Please note: **Backups are your responsibility.** These instructions assume
   the data is disposable, and do not attempt to make backups.
-    - Pull requests are welcome if you'd like to see more guidance on this.
-    - Please submit an issue if you'd like to work on enabling backups through Docker Compose.
+  - Pull requests are welcome if you'd like to see more guidance on this.
+  - Please submit an issue if you'd like to work on enabling backups through Docker Compose.
 - Your database data is stored on a docker volume, which means that it will
   persist even when you destroy all your docker containers. Be mindful of this.
-    - You can remove ALL volumes defined within a `docker-compose` file via: `docker compose down --volumes`
-    - You can remove ONE volume via `docker volume ls` and `docker volume rm <name>`
+  - You can remove ALL volumes defined within a `docker-compose` file via: `docker compose down --volumes`
+  - You can remove ONE volume via `docker volume ls` and `docker volume rm <name>`
 - SQL migrations can be found in [`server/postgres/migrations/`][] of this
   repo.
 - The path to the SQL file will be relative to its location in the docker
@@ -23,12 +23,18 @@ For example, if we add the migration file
 `server/postgres/migrations/000001_update_pwreset_table.sql`, you'd run on your
 host system:
 
-```
+```sh
 docker compose exec postgres psql --username postgres --dbname polis-dev --file=/docker-entrypoint-initdb.d/000001_update_pwreset_table.sql
 ```
 
-You'd do this for each new file, in numeric order.
+You can also run a local .sql file on a postgres container instance with this syntax:
 
-   [`server/postgres/migrations/`]: /server/postgres/migrations
+```sh
+docker exec -i polis-dev-postgres-1 psql -U postgres -d polis-dev < server/postgres/migrations/000006_update_votes_rule.sql
+```
 
+where `polis-dev-postgres-1` is the name of the running container (see the output of `docker ps`), `postgres` is the db username and `polis-dev` is the database.
 
+You'd do this for each new file, in numeric order.
+
+   [`server/postgres/migrations/`]: /server/postgres/migrations

server/postgres/migrations/000000_initial.sql

@@ -826,7 +826,7 @@ CREATE RULE on_vote_insert_update_unique_table AS
     DO ALSO
         INSERT INTO votes_latest_unique (zid, pid, tid, vote, weight_x_32767, modified)
         values (NEW.zid, NEW.pid, NEW.tid, NEW.vote, NEW.weight_x_32767, NEW.created)
-            ON CONFLICT (zid, pid, tid) DO UPDATE SET vote = excluded.vote, modified = NEW.created;
+            ON CONFLICT (zid, pid, tid) DO UPDATE SET vote = excluded.vote, modified = excluded.modified;
 
 
 CREATE TABLE crowd_mod (

server/postgres/migrations/000006_update_votes_rule.sql

@@ -0,0 +1,13 @@
+-- This migration fixes an issue with a poorly specified rule definition in the original 000000_initial.sql schema.
+-- The old specification worked on Postgres 13, but not longer does on Postgres 14.
+-- Consequently, if you set up your Polis database prior to April 9th, 2023, and wish to upgrade to Postgres 14,
+-- you should run this migration first.
+
+DROP RULE IF EXISTS on_vote_insert_update_unique_table ON votes;
+
+CREATE RULE on_vote_insert_update_unique_table AS
+    ON INSERT TO votes
+    DO ALSO
+        INSERT INTO votes_latest_unique (zid, pid, tid, vote, weight_x_32767, modified)
+        values (NEW.zid, NEW.pid, NEW.tid, NEW.vote, NEW.weight_x_32767, NEW.created)
+            ON CONFLICT (zid, pid, tid) DO UPDATE SET vote = excluded.vote, modified = excluded.modified;