send_not.plpgsql

--
CREATE OR REPLACE FUNCTION notify_event() RETURNS TRIGGER AS $$    DECLARE 
        data json;
        notification json;
    
    BEGIN
    
        -- Convert the old or new row to JSON, based on the kind of action.
        -- Action = DELETE?             -> OLD row
        -- Action = INSERT or UPDATE?   -> NEW row
        IF (TG_OP = 'DELETE') THEN
            data = row_to_json(OLD);
        ELSE
            data = row_to_json(NEW);
        END IF;
        
        -- Contruct the notification as a JSON string.
        notification = json_build_object(
                          'table',TG_TABLE_NAME,
                          'action', TG_OP,
                          'data', data);
        
                        
        -- Execute pg_notify(channel, notification)
        PERFORM pg_notify('events',notification::text);
        
        -- Result is ignored since this is an AFTER trigger
        RETURN NULL; 
    END;
    
$$ LANGUAGE plpgsql;
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