TCL SQL notify listen

start.tcl

package require Pgtcl

proc notification { d } {
  puts "notification from SQL: $d"
  # Here I expect to see
  # notification from SQL: this is a payload
}

set db [pg_connect -conninfo \
  [list host=localhost user=test dbname=test password=test]]

pg_listen $db "virtual" notification

set query {
  DO
  $BODY$
  BEGIN
    RAISE NOTICE 'doing a notification';
    NOTIFY virtual, 'this is a payload';
    -- I suggest you to check also pg_notify
  END;
  $BODY$;
}
set result [pg_exec $db $query]
if {[pg_result $result -status] != "PGRES_COMMAND_OK"} {
  puts "[pg_result $result -status] [pg_result $result -error]"
}

vwait forever