Initial SQL examples

example.sql

@@ -0,0 +1,70 @@
+-- Insert a row into pg_amqp's definition table
+INSERT INTO amqp.broker (host, vhost, username, "password") VALUES ('localhost', '/', 'guest', 'guest');
+
+-- Table
+
+CREATE TABLE presentation_example
+(
+  row_id serial NOT NULL,
+  occurred_at timestamp with time zone NOT NULL DEFAULT now(),
+  payload text
+)
+WITH (
+  OIDS=FALSE
+);
+
+-- Trigger Function
+
+CREATE OR REPLACE FUNCTION demo_trigger() RETURNS trigger AS
+$demo_trigger$
+  DECLARE
+    message text := '{"undefined": True}';
+    result record;
+  BEGIN
+    IF TG_OP = 'DELETE' THEN
+        message := $message${$message$ ||
+          $message$"operation": "delete", $message$ ||
+          $message$"event_time": "$message$ || CURRENT_TIMESTAMP || $message$",$message$ ||
+          $message$"data": { $message$ || 
+          $message$"row_id": $message$ || OLD.row_id || $message$,$message$ ||
+          $message$"occurred_at": "$message$||OLD.occurred_at || $message$",$message$ ||
+          $message$"payload": "$message$ || OLD.payload || $message$"$message$ ||
+          $message$ } }$message$;
+    ELSIF TG_OP = 'UPDATE' THEN
+        message := $message${$message$ ||
+          $message$"operation": "update", $message$ ||
+          $message$"event_time": "$message$ || CURRENT_TIMESTAMP || $message$",$message$ ||
+          $message$"old": { $message$ || 
+          $message$"row_id": $message$ || OLD.row_id || $message$,$message$ ||
+          $message$"occurred_at": "$message$||OLD.occurred_at || $message$",$message$ ||
+          $message$"payload": "$message$ || OLD.payload || $message$"$message$ ||
+          $message$ },$message$ ||
+          $message$"new": { $message$ || 
+          $message$"row_id": $message$ || NEW.row_id || $message$,$message$ ||
+          $message$"occurred_at": "$message$||NEW.occurred_at || $message$",$message$ ||
+          $message$"payload": "$message$ || NEW.payload || $message$"$message$ ||
+          $message$ } }$message$;    
+    ELSIF TG_OP = 'INSERT' THEN
+        message := $message${$message$ ||
+          $message$"operation": "insert", $message$ ||
+          $message$"event_time": "$message$ || CURRENT_TIMESTAMP || $message$",$message$ ||
+          $message$"data": { $message$ || 
+          $message$"row_id": $message$ || NEW.row_id || $message$,$message$ ||
+          $message$"occurred_at": "$message$|| NEW.occurred_at || $message$",$message$ ||
+          $message$"payload": "$message$ || NEW.payload || $message$"$message$ ||
+          $message$ } }$message$;    
+    END IF;
+    RAISE NOTICE 'Message: %', message;
+    SELECT amqp.publish(1, 'postgres', 'publish_transactions', message) INTO result;
+    RAISE NOTICE 'Result: %', result;
+    RETURN NULL;
+  END;
+$demo_trigger$ LANGUAGE plpgsql;
+
+-- Add the trigger
+
+CREATE TRIGGER demo_trigger_event
+  AFTER INSERT OR UPDATE OR DELETE
+  ON presentation_example
+  FOR EACH ROW
+  EXECUTE PROCEDURE demo_trigger();