SELECT a.prodID, a.prodName, c.Quantity, 
                                    SUM (IIF(b.operName='realiz', b.Quantity, 0)) AS Realiz,
                                    SUM (IIF(b.operName='prihod', b.Quantity, 0)) AS Prihod,
                                    SUM (IIF(b.operName='spisanie',  b.Quantity, 0)) AS Spisanie,
                                    SUM (IIF(b.operName='vozvrat', b.Quantity, 0)) AS Vozvrat
FROM   (((products a)
LEFT JOIN  operations b ON a.prodID = b.prodID)
LEFT JOIN  remains c ON a.prodID=c.prodID)
WHERE c.periodID=1
GROUP BY a.prodName,a.prodID,c.Quantity

WHERE c.periodID=1