CREATE TABLE VISITORS (
    AUTO_INC    INTEGER NOT NULL,
    ATT_ID        TMP$IDENTIFIER,
    DATE_ATT    DATE,  /*время присоед*/ 
    DATE_DET    DATE,  /*время отсоед*/ 
    USER_NAME  CHAR( 67 ) CHARACTER SET UNICODE_FSS,
    USER_IP       TMP$USER_IP_ADDR,
    USER_HOST  TMP$USER_HOST
);

CREATE TRIGGER TMP$ATTACHMENTS_AD0 FOR TMP$ATTACHMENTS
ACTIVE AFTER DELETE POSITION  0 
AS
begin
   insert into visitors (auto_inc,att_id,date_att,date_det,user_name,user_ip,user_host) values
   (gen_id(GEN_VISITORS_ID, 1 ),old.tmp$attachment_id,old.tmp$timestamp,
    current_timestamp,old.tmp$user,old.tmp$user_ip_addr,old.tmp$user_host);
end