Prefix things with "public." inside Postgres functions

Boy is this a stupid behavior of Postgres, and one that only really
manifests when restoring data from a backup.

resetdb.sh

@@ -9,8 +9,8 @@ set -eou pipefail
 # TODO(opensource): We should adapt Asaf's seedfile command and then delete this.
 
 THIS_PATH=$(pwd)
-#BETA_PATH='/mnt/c/Users/bvisn/Developer/handmade/handmade-beta'
+BETA_PATH='/mnt/c/Users/bvisn/Developer/handmade/handmade-beta'
-BETA_PATH='/Users/benvisness/Developer/handmade/handmade-beta'
+# BETA_PATH='/Users/benvisness/Developer/handmade/handmade-beta'
 
 cd $BETA_PATH
 docker-compose down -v
@@ -22,5 +22,5 @@ cd $THIS_PATH
 go run src/main.go migrate 2021-03-10T05:16:21Z
 
 cd $BETA_PATH
-#./scripts/db_import -d -n hmn_two -a ./dbdumps/hmn_pg_dump_2021-04-26
+./scripts/db_import -d -n hmn_two -a ./dbdumps/hmn_pg_dump_2021-04-26
-./scripts/db_import -d -n hmn_two -a ./dbdumps/hmn_pg_dump_2021-04-25
+# ./scripts/db_import -d -n hmn_two -a ./dbdumps/hmn_pg_dump_2021-04-25

src/migration/migrations/2021-09-05T223354Z_PublicInFunctions.go

@@ -0,0 +1,88 @@
+package migrations
+
+import (
+	"context"
+	"time"
+
+	"git.handmade.network/hmn/hmn/src/migration/types"
+	"git.handmade.network/hmn/hmn/src/oops"
+	"github.com/jackc/pgx/v4"
+)
+
+func init() {
+	registerMigration(PublicInFunctions{})
+}
+
+type PublicInFunctions struct{}
+
+func (m PublicInFunctions) Version() types.MigrationVersion {
+	return types.MigrationVersion(time.Date(2021, 9, 5, 22, 33, 54, 0, time.UTC))
+}
+
+func (m PublicInFunctions) Name() string {
+	return "PublicInFunctions"
+}
+
+func (m PublicInFunctions) Description() string {
+	return "Make sure to put the schema in front of everything inside our postgres functions"
+}
+
+func (m PublicInFunctions) Up(ctx context.Context, tx pgx.Tx) error {
+	/*
+		This is due to a really stupid behavior of Postgres where, when restoring
+		data, it apparently forgets that `tablename` is generally equivalent to
+		`public.tablename`. This makes it totally impossible for us to actually
+		restore our database backups, since these functions fail when adding new
+		rows.
+
+		https://www.postgresql.org/message-id/20180825020418.GA7869%40momjian.us
+	*/
+
+	_, err := tx.Exec(ctx, `
+		CREATE OR REPLACE FUNCTION thread_type_for_post(int) RETURNS int AS $$
+			SELECT thread.type
+			FROM
+				public.handmade_post AS post
+				JOIN public.handmade_thread AS thread ON post.thread_id = thread.id
+			WHERE post.id = $1
+		$$ LANGUAGE SQL;
+
+		CREATE OR REPLACE FUNCTION project_id_for_post(int) RETURNS int AS $$
+			SELECT thread.project_id
+			FROM
+				public.handmade_post AS post
+				JOIN public.handmade_thread AS thread ON post.thread_id = thread.id
+			WHERE post.id = $1
+		$$ LANGUAGE SQL;
+	`)
+	if err != nil {
+		return oops.New(err, "failed to add post constraints")
+	}
+
+	return nil
+}
+
+func (m PublicInFunctions) Down(ctx context.Context, tx pgx.Tx) error {
+	_, err := tx.Exec(ctx, `
+		CREATE OR REPLACE FUNCTION thread_type_for_post(int) RETURNS int AS $$
+			SELECT thread.type
+			FROM
+				handmade_post AS post
+				JOIN handmade_thread AS thread ON post.thread_id = thread.id
+			WHERE post.id = $1
+		$$ LANGUAGE SQL;
+
+		CREATE OR REPLACE FUNCTION project_id_for_post(int) RETURNS int AS $$
+			SELECT thread.project_id
+			FROM
+				handmade_post AS post
+				JOIN handmade_thread AS thread ON post.thread_id = thread.id
+			WHERE post.id = $1
+		$$ LANGUAGE SQL;
+	`)
+	if err != nil {
+		return oops.New(err, "failed to add post constraints")
+	}
+
+	return nil
+}