docs: update docs and some of the scripts that run them (#1560)

Author: samrose

flake.nix

@@ -951,6 +951,7 @@
           ];
           shellHook = ''
             export HISTFILE=.history
+            export DATABASE_URL="postgres://supabase_admin@localhost:5435/postgres?sslmode=disable"
           '';
         };
         cargo-pgrx_0_11_3 = mkCargoPgrxDevShell {

migrations/README.md

@@ -85,20 +85,24 @@ First, start a local postgres server in another terminal window:
 nix run .#start-server 15
 ```
 
-Then, in your main terminal window:
+Then, in your main terminal window, run:
 
 ```shell
-# Set up the database URL for migrations
-export DATABASE_URL="postgres://supabase_admin@localhost:5435/postgres?sslmode=disable"
 
+nix develop
+```
+in the root of `supabase/postgres`. 
+
+Next run: 
+``` shell
 # Create a new migration (make sure to specify the migrations directory)
 dbmate --migrations-dir="migrations/db/migrations" new '<some message>'
 ```
 
 Then, execute the migration at `./migrations/db/xxxxxxxxx_<some_message>` and make sure it runs successfully with:
 
 ```shell
-dbmate up
+dbmate --no-dump-schema --migrations-dir"migrations/db/migrations" up
 ```
 
 Note: Migrations are applied using the `supabase_admin` superuser role, as specified in the "How it was Created" section above.

nix/tools/dbmate-tool.sh.in

@@ -189,8 +189,15 @@ perform_dump() {
     while [ $attempt -le $max_attempts ]; do
         echo "Attempting dbmate dump (attempt $attempt/$max_attempts)"
 
+        # Run dbmate dump
         if dbmate dump; then
-            return 0
+            # Post-process schema.sql to remove schema_migrations INSERT statements
+            if [ -f "db/schema.sql" ]; then
+                # Remove INSERT INTO schema_migrations lines
+                sed -i '/^INSERT INTO schema_migrations/d' db/schema.sql
+                echo "Schema dump completed successfully (schema_migrations data removed)"
+                return 0
+            fi
         fi
 
         echo "Dump attempt $attempt failed, waiting before retry..."