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Asked: 2026-05-21T23:44:12+00:00

I’m using Amazon’s SimpleDB Java client to read data from SimpleDB. The problem I

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I’m using Amazon’s SimpleDB Java client to read data from SimpleDB. The problem I have is even though I specified the columns in the some order in the SelectRequest like the following:

SelectRequest req = new SelectRequest("SELECT TIMESTAMP, TYPE, APP, http_status, USER_ID from mydata");
SElectResult res = _sdb.select(req);
..

It returned data in following column order:

 APP, TIMSTAMP, TYPE, USER_ID, http_status,

It seems it automatically reordered the columns in ascend order. Is there any way I can force the order as I specified in the select clause?

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1 Answer

  1. Editorial Team

    The columns returned are not an ordered list but an unordered set of attributes. You can’t control the order they come back in. SELECT is designed to work even in cases where some of the attributes in your query don’t exist for every (or any) returned items. In those cases specifically you wouldn’t be able to rely on order anyway. I realize that’s small consolation if you have structured your data set so that the attributes are always present.

    However, since you know the desired order ahead of time, it should be pretty easy to pull the data out of the result in the proper order. It’s just XML after all, or in the case of the Java client, freshly parsed XML.

    The Select operation returns a set of Attributes for ItemNames that match the select expression.

    SimpleDB docs for SELECT

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