MYSQL查询包含最新结果

I want to create a query statement for MYSQL which will give me the most recent price of an item. A table contains a bunch of prices (UnitPrice) paired with each item (MIL_id). However, I want the most recent price (UnitPrice) for each item (MIL_id). Each row also has a ReqNum column which increments for each entry and a Date column for each entry. So how can I make a query which will give me the most recent price (UnitPrice) with the newest Date or ReqNum?

What I have so far:

SELECT t1.VendorPtNum, t1.UnitPrice, MAX(t1.Date), MAX(t1.ReqNum), t2.MIL_id
FROM tblMatInvList t2
LEFT JOIN tblPurchaseReq t1 ON t1.VendorPtNum = t2.VendPtNum
GROUP BY t2.MIL_id
HAVING MAX(t1.Date)

EDIT after your comment:

So, you have a table

tblMatInvList

--------------------+

VendorPtNum | MIL_id

--------------------+

and a table

tblPurchaseReq

---------------------------------------+

VendorPtNum | UnitPrice | Date | ReqNum

---------------------------------------+

I think you can use something like this

SELECT * FROM tblMatInvList
INNER JOIN 
      (SELECT MAX(Date) as date,
              VendorPtNum
         FROM tblPurchaseReq
         GROUP BY tblPurchaseReq.VendorPtNum) prices
ON prices.VendorPtNum = tblMatInvList.VendorPtNum;