Памогите разобраться в запросах SQL

///myconst - это я так понял таблица
SELECT 
Const.UNP,
Const.NaimOrg, 
Const.RS, Const.Kodbanka, 
IIf([cbu]=0,[NameBanka],[NameCBU]) AS Bank, 
Const.Adress, 
IIf([cbu]=0,[adresBanka],[adressCBU]) AS BankAdress, 
Const.PunktPogruzki,TunitID,GRMunitID 
FROM 
(Const LEFT JOIN Banki ON Const.Kodbanka = Banki.KodBanka)
LEFT JOIN CBU ON Const.CBU = CBU.id_cbu;
 
//TTN - это я так понял таблица
SELECT 
TTN.Nomblank, 
TTN.ddDoc, 
TTN.avto, 
TTN.putL, 
TTN.vladTR, 
TTN.Voditel, 
TTN.Osnovanie, 
TTN.PunktPogr, 
TTN.PunktRazgr, 
TTN.Pricep, 
otpRazreshil.apointment AS ORDolg, 
otpRazreshil.FIO AS ORFIO, 
OtpProizvel.apointment AS OPDolg, 
OtpProizvel.FIO AS OPFIIO, 
TTN.Ekspiditor, 
TTN.VidDover, 
TTN.SposobPogr, 
TTN.Tprib, 
TTN.tUb, 
TTN.KolEzdok, 
TTN.Prostoy, 
 TTN.Docs, 
 TTN.dover, 
 TTN.Pogruzka, 
 GP.unp AS UNPGruzopoluch, 
 GP.NamePred AS NameGruzopoluchatel, 
 GP.Adress AS AdressGruzopoluch, 
 GP.RS AS RSGruzopoluch, 
 GP.KodBanka AS KodBankaGruzopoluch, 
 IIf([GP]![CBU]=0,[GPBank]![Namebanka],
 [GPCBU]![NameCBU]) AS GPBANK, 
 IIf([GP]![CBU]=0,[GPBank]![adresbanka],[GPCBU]![AdressCBU]) AS GPBANKAdress, 
 ZK.unp AS UNPZK, 
 ZK.NamePred AS NameZK, 
 ZK.Adress AS adressZK, 
 ZK.RS AS RSZK, 
 ZK.KodBanka AS KodBankaZK, 
 IIf([ZK]![CBU]=0,[ZKBank]![Namebanka],[ZKCBU]![NameCBU]) AS ZKBANK, 
 IIf([ZK]![CBU]=0,[ZKBank]![adresbanka],[ZKCBU]![AdressCBU]) AS ZKBANKAdress, 
 TTN.iddoc, 
 TTN.PrintRS, 
 SposobPogr.Pogr,
 idcur,
 zakazchik,
 printprinyl 
FROM (((((((TTN LEFT JOIN (Predpr AS GP 
LEFT JOIN Banki AS GPBANK ON GP.KodBanka = GPBANK.KodBanka) ON TTN.Gruzopoluch = GP.idpred) 
LEFT JOIN CBU AS GPCBU ON GP.CBU = GPCBU.id_cbu) 
LEFT JOIN Predpr AS ZK ON TTN.Zakazchik = ZK.idpred) 
LEFT JOIN Banki AS ZKBank ON ZK.KodBanka = ZKBank.KodBanka) 
LEFT JOIN CBU AS ZKCBU ON ZK.CBU = ZKCBU.id_cbu) 
LEFT JOIN Sotr AS otpRazreshil ON TTN.OtpuskRazreshil = otpRazreshil.idsotr) 
LEFT JOIN Sotr AS OtpProizvel ON TTN.OtpuskProizvel = OtpProizvel.idsotr) 
LEFT JOIN SposobPogr ON TTN.SposobPogr = SposobPogr.idpogr
WHERE (((TTN.iddoc)=:@id));
 
///TABLE TTN - это я так понял таблица
SELECT 
Products.ProductName, 
TableTTN.Kol, 
TableTTN.prise, 
TableTTN.Amnt, 
TableTTN.stnds, 
TableTTN.amntNDS, 
TableTTN.Vsego, 
Units.UnitName, 
IIf([kountinpack]>0,Round([kol]/[kountinpack],0),0) AS KolGM, 
IIf([kountinpack]>0,Round([kol]/[kountinpack]*[massa],
IIf(DLast('[okrmassubrutto]','[const]')=TRUE,0,CInt(DLast('[UnitRound]','[units]','[Unitid]=' & DLast('[TunitID]','[const]'))))),0) AS MassaBrutto, 
TableTTN.description, 
TableTTN.idttn
FROM ((TableTTN LEFT JOIN Products ON TableTTN.idproduct = Products.idProduct) LEFT JOIN Units ON Products.Unit = Units.UnitId) LEFT JOIN Units AS BoxUnits ON Products.BoxUnit = BoxUnits.UnitId
WHERE (((TableTTN.idttn)=:@id))
ORDER BY idz;[TABLE][/TABLE]