求教这个sql怎么写？

[tababy]

product_name saled_num sale_date
------------ --------- ---------
toy 100 2001-12-12
toy 50 2001-12-02
ink 60 2001-12-05
ink 70 2001-12-09
线在我想得到每个产品最近的销售记录，如
toy 100 2001-12-12
ink 70 2001-12-09
这个sql怎么写？

[acnode]

select distinct product_name,saled_num,sale_date from tablename order by sale_date

[smartbigcat]

select * from <tablename> a
where sale_date=
(select max(sale_date) from <tablename> b
where a.product_name=b.product_name
group by product_name)

[rwq_]

select product_name,saled_num,sale_date from table where (sale_date,product_name) in(select max(sale_date),product_name from table group by product_name;
试试看！

[whitegourd]

试试：select distinct product_name from table order by sale_date

[huang_sir]

Select TableName.Prodcut_Name,TableName.Saled_Num,TableName.Sale_Date From
TableName,(Select Product_Name,Max(Sale_Date) As NewDate From TableName) As S
Where TableName.Product_Name=S.Product_Name And TableName.Sale_Date=S.NewDate

[huang_sir]

Sorry,It Is Right:
Select TableName.Prodcut_Name,TableName.Saled_Num,TableName.Sale_Date From
TableName,(Select Product_Name,Max(Sale_Date) As NewDate From TableName
Group By Product_Name) As S
Where TableName.Product_Name=S.Product_Name And TableName.Sale_Date=S.NewDate

[hanyu010]

如果你的日期字段还有时分秒的话（在oracle中有）可：
select * from tablename a where (product_name,sale_date) in (select
product_name,max(sale_date) from tablename b group by product_name);