Hey, If the order ids are variable, then you will have to use a separator. You then can use a start of 'foo:' and a prefix filter of 'foo:'.
The start,end key wont work with variable length in this way. But the good news is prefix filter is very efficient. Good luck! -ryan On Tue, Dec 14, 2010 at 3:28 PM, Bryan Keller <[email protected]> wrote: > I had a question about using a Scan on part of a composite key. Say I have > order line item rows, and the ID is order ID + line item ID. Each ID is a > random string. I want to get all line items for an order with my Scan object. > > Setting the startRow on Scan is easy enough, just set it to the order ID and > leave off the line item ID. However, because endRow is exclusive, I need to > come up with a key that is just past the order ID. This would be > straightforward if the keys are numeric (just add one to the order ID), but > becomes kind of a kludge when the keys are strings. > > Right now I build the keys with a byte separator between the two strings and > set it to 0 when storing. Then when I want to scan, I create the startRow > with the Order ID + (byte)0, and the endRow with Order ID + (byte)1. Seems > like kind of a waste to have that extra byte just for this purpose, though. > Is there a better approach, like specifying the endRow inclusively?
