From 3c4b217364f2c17fac532e0a51793e2a23663c93 Mon Sep 17 00:00:00 2001
From: "Sascha L. Teichmann" <sascha.teichmann@intevation.de>
Date: Mon, 28 Feb 2022 11:38:16 +0100
Subject: [PATCH] pg listen/notify part

---
 pg/send_block_changes.sql | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 pg/send_block_changes.sql

diff --git a/pg/send_block_changes.sql b/pg/send_block_changes.sql
new file mode 100644
index 0000000..5017c0b
--- /dev/null
+++ b/pg/send_block_changes.sql
@@ -0,0 +1,23 @@
+BEGIN;
+
+  CREATE OR REPLACE FUNCTION send_block_changes()
+  RETURNS TRIGGER AS
+$$
+BEGIN
+  PERFORM pg_notify('blockchanges',
+    json_build_object(
+      'X', NEW.posx,
+      'Z', NEW.posz
+    )::text
+  );
+  RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER blocks_changed
+  AFTER INSERT OR UPDATE
+  ON blocks
+  FOR EACH ROW
+  EXECUTE PROCEDURE send_block_changes();
+
+END;