qBIDS.Append;
//Заполняем мастер-запись
...
  qBIDS.FieldByName('BCAID').AsInteger:=edrCAID.Properties.Value;
...
  qBIDS.post;
  trsOrdWr.StartTransaction;
  try
    qBIDS.ApplyUpdates;
//vvvvvvvvvvv
    BID:=qBIDS.FieldByName('BID').AsLargeInt; //Хотим тут сохранить присвоенное сервером значение автоинкрементного поля
//^^^^^^^^ вот ключевая строка - значение аввтоинкрементного поля - 0. Делать коммит? 
// а если на следующих строках будет ошибка? мастер запись останется, детейлы - нет

//Хотим перебрать детейл-записи и прописать у них ИД родительской мастер-записи
    qBIS.First;
    while not qBIS.eof do
    begin
      qBIS.Edit;
      qBIS.FieldByName('BIBID').AsLargeInt:=BID;
      qBIS.Post;
      qBIS.next;
    end;
    qBIS.ApplyUpdates;
    trsOrdWr.Commit;
except
    trsOrdWr.Rollback;
end

INSERT INTO BIDS
(BCAID, BFROM, BTO, BDATE, BDEADLINE, 
  BEXECUTED, BCANCELED, BEMPSTART, BEMPEXEC, 
  BEMPEND, BNOTES, BTYPE, BRESULT, BPRIORITY, 
  BSTART, BEND, BADR, BNAME, BPHONE, 
  BPAYTYPE, BADD, BPREPAYED, BPREPAYSUM, 
  BSTATUS, BORDERID)
VALUES (:NEW_BCAID, :NEW_BFROM, :NEW_BTO, :NEW_BDATE, :NEW_BDEADLINE, 
  :NEW_BEXECUTED, :NEW_BCANCELED, :NEW_BEMPSTART, :NEW_BEMPEXEC, 
  :NEW_BEMPEND, :NEW_BNOTES, :NEW_BTYPE, :NEW_BRESULT, :NEW_BPRIORITY, 
  :NEW_BSTART, :NEW_BEND, :NEW_BADR, :NEW_BNAME, :NEW_BPHONE, 
  :NEW_BPAYTYPE, :NEW_BADD, :NEW_BPREPAYED, :NEW_BPREPAYSUM, 
  :NEW_BSTATUS, :NEW_BORDERID)
RETURNING /*вот автоинкрементное поле от сервера*/BID,/*будь оно не ладно */ DBDATE, BPRIORITY, _BFROMNAME, _BTONAME, _BCANAME, _EMPSTART, _EMPEXEC, _EMPEND, _PAYTYPE, _BTYPE, _PRIORITY, BSTATUS, _STATUS, _ITEMS

CREATE TABLE BIDS (
    BID           D_REGID GENERATED BY DEFAULT AS IDENTITY /* D_REGID = BIGINT NOT NULL */,
    BCAID         D_ID /* D_ID = INTEGER NOT NULL */,
    BFROM         D_ID NOT NULL /* D_ID = INTEGER NOT NULL */,
    BTO           D_ID /* D_ID = INTEGER NOT NULL */,
    BDATE         D_TS /* D_TS = TIMESTAMP */,
    BDEADLINE     D_TS /* D_TS = TIMESTAMP */,
    BEXECUTED     D_TS /* D_TS = TIMESTAMP */,
    BCANCELED     D_TS /* D_TS = TIMESTAMP */,
    BEMPSTART     D_ID /* D_ID = INTEGER NOT NULL */,
    BEMPEXEC      D_ID /* D_ID = INTEGER NOT NULL */,
    BEMPEND       D_ID /* D_ID = INTEGER NOT NULL */,
    DBDATE        D_TS DEFAULT current_timestamp NOT NULL /* D_TS = TIMESTAMP */,
    BNOTES        D_TB /* D_TB = BLOB SUB_TYPE 1 SEGMENT SIZE 80 */,
    BTYPE         D_ID /* D_ID = INTEGER NOT NULL */,
    BRESULT       D_ID /* D_ID = INTEGER NOT NULL */,
    BPRIORITY     D_ID DEFAULT 1 NOT NULL /* D_ID = INTEGER NOT NULL */,
    BSTART        D_TS /* D_TS = TIMESTAMP */,
    BEND          D_TS /* D_TS = TIMESTAMP */,
    BADR          D_NAME /* D_NAME = VARCHAR(100) */,
    BNAME         D_NAME /* D_NAME = VARCHAR(100) */,
    BPHONE        D_NAME /* D_NAME = VARCHAR(100) */,
    BPAYTYPE      D_ID /* D_ID = INTEGER NOT NULL */,
    BADD          D_PATH /* D_PATH = VARCHAR(1000) */,
    BPREPAYED     D_TS /* D_TS = TIMESTAMP */,
    BPREPAYSUM    D_SUM /* D_SUM = DECIMAL(18,2) */,
    "_BFROMNAME"  COMPUTED BY ((select caname from cas where caid=bfrom)),
    "_BTONAME"    COMPUTED BY (((select caname from cas where caid=bto))),
    "_BCANAME"    COMPUTED BY (((select caname from cas where caid=bcaid))),
    "_EMPSTART"   COMPUTED BY ((select caname from cas where bEMPSTART=caid)),
    "_EMPEXEC"    COMPUTED BY ((select caname from cas where bEMPexec=caid)),
    "_EMPEND"     COMPUTED BY ((select caname from cas where bEMPEND=caid)),
    "_PAYTYPE"    COMPUTED BY ((select ptname from paytypes where ptid=bpaytype)),
    "_BTYPE"      COMPUTED BY ((select btname from bidtypes where btid=btype)),
    "_PRIORITY"   COMPUTED BY ((select prname from priorities where prid=bpriority)),
    BSTATUS       D_ID DEFAULT 1 NOT NULL /* D_ID = INTEGER NOT NULL */,
    "_STATUS"     COMPUTED BY ((select bsname from bidstatus where bstatus=bsid)),
    "_ITEMS"      BLOB SUB_TYPE 1 COMPUTED BY ((select list("_BRIEFART" || ': ' || BICNT, ascii_char(13)) as BI 
from BIDIT where BIBID = BID)),
    BORDERID      D_BIGINT /* D_BIGINT = BIGINT */
);