SELECT
  ProductTimeConstraint.numberOfDays
INTO
  :numberOfDays 
FROM
  
  ( 
  SELECT
    MAX(fromDate) AS maxFromDate 
  FROM
    
    ( 
    SELECT
      fromDate 
    FROM
      ProductDelivery,
      ProductTimeConstraint 
    WHERE fromDate IS NOT NULL 
      AND fromDate <= :constraintDate 
      AND ProductDelivery.caseID = :caseID 
      AND ProductTimeConstraint.productID = ProductDelivery.productID 
      AND ProductTimeConstraint.constraintType = :constraintType 
      AND ProductTimeConstraint.recordStatus = :recordStatus 
    ) temp 
  ) maxitems,
  ProductDelivery,
  ProductTimeConstraint 
WHERE 
  (
    
    (
      maxFromDate IS NOT NULL 
      AND maxFromDate = ProductTimeConstraint.fromDate 
    ) 
    OR 
    (
      maxFromDate IS NULL 
      AND ProductTimeConstraint.fromDate IS NULL 
    ) 
  ) 
  AND ProductDelivery.caseID = :caseID 
  AND ProductTimeConstraint.productID = ProductDelivery.productID 
  AND ProductTimeConstraint.constraintType = :constraintType 
  AND ProductTimeConstraint.recordStatus = :recordStatus