CREATE GENERATOR GENR$STR_ID;

CREATE TABLE TABL$STR (
    OBJ_ID       DOMN$PSTRING_50_ID,  -- Имя таблицы, для которой храним строку
    REC_ID       DOMN$PSTRING_50_ID,  -- ID-записи, для которой храним строку
    ID           DOMN$INTEGER_ID, -- Универсальный идентификатор
    NAME         DOMN$PSTRING, -- какое-то примечание к строке. может, тебе не надо.
    DECR         DOMN$BLOB_TEXT, -- сама строка.
    DATE_COMMIT  DOMN$DATETIME, -- дата добавления/изменения записи
    USER_ID      DOMN$PSTRING_50 -- пользователь, последним добавивший или редактировавший строку
);
/******************************************************************************/
/***                              Primary Keys                              ***/
/******************************************************************************/
ALTER TABLE TABL$STR ADD CONSTRAINT C_PK$STR_ID PRIMARY KEY (ID)
USING INDEX INDX$STR_ID;
/******************************************************************************/
/***                                Indices                                 ***/
/******************************************************************************/

CREATE INDEX INDX$STR_DATE_COMMIT ON TABL$STR (DATE_COMMIT);
CREATE INDEX INDX$STR_OBJ_ID ON TABL$STR (OBJ_ID);
CREATE INDEX INDX$STR_REC_ID ON TABL$STR (REC_ID);
CREATE INDEX INDX$STR_USER_ID ON TABL$STR (USER_ID);
/******************************************************************************/
/***                                Triggers                                ***/
/******************************************************************************/
SET TERM ^ ;

CREATE OR ALTER TRIGGER TRIG$STR_ADIU_255 FOR TABL$STR
ACTIVE AFTER INSERT OR UPDATE OR DELETE POSITION 255
AS
BEGIN
   POST_EVENT 'TABL$STR';
END
^
CREATE OR ALTER TRIGGER TRIG$STR_BIU_200 FOR TABL$STR
ACTIVE BEFORE INSERT OR UPDATE POSITION 200
AS
BEGIN
  IF(NEW.DATE_COMMIT IS NULL)THEN NEW.DATE_COMMIT = CURRENT_TIMESTAMP;
  IF(NEW.USER_ID     IS NULL)THEN
    BEGIN
    NEW.USER_ID = RDB$GET_CONTEXT('USER_SESSION', 'DATABASE_USER');
    END
  IF(NEW.USER_ID     IS NULL)THEN
    BEGIN
    NEW.USER_ID = CURRENT_USER;
    END
END
^
CREATE OR ALTER TRIGGER TRIG$STR_BI_000 FOR TABL$STR
ACTIVE BEFORE INSERT POSITION 0
AS
BEGIN
  NEW.ID = GEN_ID(GENR$STR_ID, 1);
END
^
SET TERM ; ^
COMMIT;

/******************************************************************************/
/***                               Privileges                               ***/
/******************************************************************************/
GRANT UPDATE, REFERENCES ON TABL$STR TO TRIGGER TRIG$STR_ADIU_255;
GRANT UPDATE, REFERENCES ON TABL$STR TO TRIGGER TRIG$STR_BIU_200;
GRANT UPDATE, REFERENCES ON TABL$STR TO TRIGGER TRIG$STR_BI_000;
COMMIT;