i have two tables, customer and transaction.Both have primary key as id.The customer table have one field created_at. and the transaction table have one field points.

I need to take the sum(points) from transaction but that will be the created_at > "2010-12-11". But query gives error.....

how will take this using join....?

amvis:

What query? What error? How do customer and transaction tables relate?

Do you want the sum of all points of all customers that were created
after Dec.11, 2010?

SELECT sum(points) AS totalpoints
FROM transaction
INNER JOIN customer ON customer.id=transaction.cid
WHERE created_at > "2010-12-11"

assuming that transaction.cid is foreign key for customer.id



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Erick