How to get rows with max date when grouping in MySQL?

Question

I have a table with prices and dates on product:

id
product
price
date

I create a new record when price change. And I have a table like this:

id product price date
1  1       10    2014-01-01
2  1       20    2014-02-17
3  1        5    2014-03-28
4  2       25    2014-01-05
5  2       12    2014-02-08
6  2       30    2014-03-12

I want to get last price for all products. But when I group with "product", I can't get a price from a row with maximum date.

I can use MAX(), MIN() or COUNT() function in request, but I need a result based on other value.

I want something like this in final:

product price date
1        5    2014-03-28
2       30    2014-03-12

But I don't know how. May be like this:

SELECT product, {price with max date}, {max date}
FROM table
GROUP BY product

Answer 1

Alternatively, you can have subquery to get the latest get for every product and join the result on the table itself to get the other columns.

SELECT  a.*
FROM    tableName a
        INNER JOIN 
        (
            SELECT  product, MAX(date) mxdate
            FROM    tableName
            GROUP   BY product
        ) b ON a.product = b.product
                AND a.date = b.mxdate

Answer 2

You can use a subquery that groups by product and return the maximum date for every product, and join this subquery back to the products table:

SELECT
  p.product,
  p.price,
  p.date
FROM
  products p INNER JOIN (
    SELECT
      product,
      MAX(date) AS max_date
    FROM
      products
    GROUP BY
      product) m
  ON p.product = m.product AND p.date = m.max_date