/**

 * Firebird 2.5

 */

-- 1.Create new fields

ALTER TABLE some_table

  ADD id INTEGER DEFAULT 0 NOT NULL,

  ADD foo_dummy CHAR(1);

-- 2.Create generador

CREATE GENERATOR some_table_id_gen;

-- 3.Create temp trigger

SET TERM ^ ;

CREATE TRIGGER some_table_temp_trgr FOR some_table

ACTIVE BEFORE UPDATE POSITION 0

AS 

BEGIN 

  new.id = GEN_ID(some_table_id_gen, 1);

END^

SET TERM ; ^ 

-- 4.Update foo_dummy field and so set the sequency

--   into field ID

UPDATE some_table SET foo_dummy = '1';

-- 5.Drop temp trigger and foo_dummy

DROP TRIGGER some_table_temp_trgr;

ALTER TABLE some_table DROP foo_dummy;

-- 6.Drop previous non ID primary key

ALTER TABLE some_table DROP CONSTRAINT some_table_current_pk;

-- 7.Create new PK

ALTER TABLE some_table ADD CONSTRAINT some_table_pk PRIMARY KEY (ID);

-- 9.Create new trigger for mantaining new PK

SET TERM !! ;

CREATE TRIGGER some_table_set_id FOR some_table

BEFORE INSERT POSITION 0 AS

BEGIN

  NEW.id = GEN_ID(some_table_id_gen, 1);

END !!

SET TERM ; !!

 

/* */

Best regards,

Hernando.