ORACLE 截断字符串

create or replace procedure ModifyLadingItemPack
(
ASoditemguid varchar2,                  --合同电子仓单明细GUID
ALadingitemGUID varchar2,               --提单子项GUID
ACDResID varchar2,                      --电子仓单号
APackageIDList varchar2,                --仓单捆包具体GUID列表
Aladingnum float,
Aladingpieces float,
AReturnValue out integer                --返回值:
)
is
ALadingItem_PackagesGUID varchar(32);
ATempIDList varchar2(4000);
AID varchar2(32);
APackageWeight float;
APackagePiece float;
ATotalPackWeight float;
begin
AReturnValue := 1;
ATempIDList := APackageIDList;
APackageWeight :=0;
APackagePiece :=0;    ---------------------------------更新合同电子仓单明细---------------------------
while ( INSTR(ATempIDList,':' ) > 0 ) or ( LENGTH(ATempIDList ) > 0 ) loop
        if INSTR(ATempIDList,':' ) > 0 then            select sys_guid() into ALadingItem_PackagesGUID from dual;
           AID := SUBSTR(ATempIDList ,1,INSTR( ATempIDList,':') - 1 );
           ATempIDList := SUBSTR(ATempIDList,INSTR( ATempIDList,':') + 1 , LENGTH(ATempIDList) - INSTR(ATempIDList,':'));            ---------------------------------提单捆包明细----------------------------------
           insert into HT_LadingItem_packages(sGUID, sLadingItemGUID, sCDResID, sPackageID)
          values(ALadingItem_PackagesGUID, ALadingitemGUID, ACDResID,AID);            ---------------------------------更新仓单捆包明细状态---------------------------
           UPDATE ZY_Packages SET state = 5 WHERE SGUID = AID;            select fWeight into ATotalPackWeight from ZY_Packages where sGUID=AID;            APackageWeight:=APackageWeight+ATotalPackWeight;
           APackagePiece:=APackagePiece+1;
        else
           AID := ATempIDList;
           ATempIDList := '';
        end if;
   end loop;    update HT_SODItem set fLadingNum=fLadingNum+APackageWeight,fLadingPieces=fLadingPieces+APackagePiece
   where sGUID=ASoditemguid; COMMIT;
EXCEPTION
WHEN OTHERS THEN BEGIN
    AReturnValue := 99;
    ROLLBACK;
END;
end;