David Garamond wrote:
Dear SQL masters,
The query for "latest price for each product" goes like this (which I
can grasp quite easily):
SELECT * FROM price p1
WHERE ctime=(SELECT MAX(ctime) FROM price p2 WHERE p1.product_id=p2.product_id)
or:
SELECT * FROM price p1
WHERE NOT EXISTS (SELECT * FROM price p2 WHERE
p1.product_id=p2.product_id AND p1.ctime < p2.ctime)
but how do yo query for "latest 3 prices for each product"? The
"price" table contains current price as well as price histories.
Is this what you are looking for...
SELECT * FROM price p1
WHERE ctime in (SELECT ctime FROM price p2 WHERE
p1.product_id=p2.product_id ORDER BY ctime DESC LIMIT 3)
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