Работа триггера

CREATE TABLE TREE (
    IDCLIENT   IDUSER NOT NULL, 
    IDPARENT   IDUSER,
    CCOUNT     INTEGER DEFAULT 0, /* кол-во прямых потомков */
    LEVEL1     INTEGER DEFAULT 0, /* уровень вложенности */
);

CREATE TRIGGER TREE_BU FOR TREE
ACTIVE BEFORE UPDATE POSITION 0
AS
begin
 if (old.IDPARENT <> new.IDPARENT) then
   begin
    UPDATE tree D SET D.CCOUNT = D.CCOUNT - 1 WHERE D.IDCLIENT = old.IDPARENT;
    UPDATE tree D SET D.CCOUNT = D.CCOUNT +1 WHERE D.IDCLIENT = new.IDPARENT;
    SELECT MAX(D1.level1)+1 FROM tree D1 WHERE D1.IDCLIENT = new.IDPARENT INTO new.level1;
   end
end

CREATE TRIGGER BI_ACOUNTS FOR ACOUNTS
ACTIVE BEFORE INSERT POSITION 0
as
DECLARE VARIABLE C INTEGER;
begin
  SELECT A.KID_LEVEL
  FROM ACOUNTS A
  WHERE (A.KOD = NEW.PARENT)
  INTO :C;
  C = :C + 1;
  IF(NEW.KID_LEVEL <> :C) THEN NEW.KID_LEVEL = :C;
end


CREATE TRIGGER AI_ACOUNTS FOR ACOUNTS
ACTIVE AFTER INSERT POSITION 0
AS
BEGIN
  UPDATE ACOUNTS A
  SET A.KID_COUNT = A.KID_COUNT + 1
  WHERE (A.KOD = NEW.PARENT);
END

/*-----------------------------------------------------------------------*/

CREATE TRIGGER BU_ACOUNTS FOR ACOUNTS
ACTIVE BEFORE UPDATE POSITION 0
as
DECLARE VARIABLE C INTEGER;
begin
 IF(NEW.PARENT <> OLD.PARENT) THEN BEGIN
  SELECT S.KID_LEVEL
  FROM ACOUNTS S
  WHERE (S.KOD = NEW.PARENT)
  INTO :C;
  C = :C + 1;
  IF(NEW.KID_LEVEL <> :C) THEN NEW.KID_LEVEL = :C;
 END
end

CREATE TRIGGER AU_ACOUNTS FOR ACOUNTS
ACTIVE AFTER UPDATE POSITION 0
AS
DECLARE VARIABLE C INTEGER;
BEGIN

 IF(NEW.PARENT <> OLD.PARENT) THEN BEGIN
     UPDATE ACOUNTS A
      SET A.KID_COUNT = A.KID_COUNT - 1
      WHERE (A.KOD = OLD.PARENT);
     UPDATE ACOUNTS A
      SET A.KID_COUNT = A.KID_COUNT + 1
      WHERE (A.KOD = NEW.PARENT);
   END

  IF(NEW.KID_LEVEL <> OLD.KID_LEVEL) THEN BEGIN
   C = NEW.KID_LEVEL + 1;
   UPDATE ACOUNTS S
   SET S.KID_LEVEL = :C
   WHERE (S.PARENT = NEW.KOD) AND (NEW.KOD <> NEW.PARENT);
  END 

END
/*------------------------------------------------------------------------*/

CREATE TRIGGER AD_ACOUNTS FOR ACOUNTS
ACTIVE AFTER DELETE POSITION 0
AS
BEGIN
  UPDATE ACOUNTS A
  SET A.KID_COUNT = A.KID_COUNT - 1
  WHERE (A.KOD = OLD.PARENT);
END