Linq To SimpleDB

NEW POST: Integer handling

SoerenNielsen — Fri, 11 Apr 2008 07:23:50 GMT

Hi

I saw your blog post on Linq, SimpleDB and integers.

It got me thinking and there seem to be two problems (sorry if you already handled these cases):

1. Zero-padding to ensure lexicographical comparision. That is fairly easy and the number of paddings you need should be easy to extract from the datatype in use. E.g. Int32 will need 10 digits at the most (11 for sign).
It might be an idea to store the numbers in the hex equivalents as you would need a lot less digits then.

2. Negative numbers.
What you want is to be able to query for numbers and have < and > work properly.
I see two solutions for this:

2a) If you are working with signed Int32 then begin to work with unsigned Int32 instead, and the number you add should be uint32.Max/2, then you can handle everything that int32 can handle. Same scheme will work for decimals, etc.

2b) If you "encode" your numbers this way, everything should work as expected, but you of course need to handle the encoding/decoding automatically.
First, pad all positive numbers as before, but add an extra "0"
Second, negative numbers have one less padding - instead they start with "-"
Third, the digits in the negative number are reversed, so the padding actually is to the right of the number.
Example:
(4+1 digit for clarity)

1 = 00001
20 = 00020

-1 = -1000
-20= -0200

Please note that "-" has a lower ascii number than "0", so you should add an extra "0" to the positive numbers.

Either way could handle your integer problem. What to choose? Your choice.

UPDATED WIKI: Home

jetheredge — Thu, 24 Jan 2008 04:11:09 GMT

Project Description
A Linq provider for Amazon SimpleDB

http://www.codethinked.com

A release is now available, documentation will follow soon. In the meantime, please check out the test project and this post:
http://www.codethinked.com/post/2008/01/LinqToSimpleDB-Preview.aspx for more details on how to use it.

UPDATED RELEASE: Alpha 1 (Jan 23, 2008)

Thu, 24 Jan 2008 04:08:16 GMT

!! Release Alpha 1

This is the first release of the Linq To SimpleDB provider. While it does have good test coverage, it has not been tested in a high load environment. Please provide feedback and report all bugs. I will provide tutorials on my blog (http://www.codethinked.com) and I will post them on this project as they are done.

Included Functionality:
* Query SimpleDB Items by Attributes
* Retrieve Attributes for items
* Query items by Name
* Create and Delete Domains
* Create and Delete Items
* Create and Delete Attributes

Source code checked in

jetheredge — Thu, 24 Jan 2008 03:59:14 GMT

Source code checked in

jetheredge — Thu, 24 Jan 2008 03:50:09 GMT

Source code checked in

jetheredge — Thu, 24 Jan 2008 03:25:04 GMT

Added ability to query Items by Name, also added context method to do the same.

UPDATED WIKI: Home

jetheredge — Wed, 23 Jan 2008 04:06:01 GMT

Project Description
A Linq provider for Amazon SimpleDB

No official release is available, but please feel free to download the latest source release and provide feedback.

http://www.codethinked.com

UPDATED WIKI: Home

jetheredge — Wed, 23 Jan 2008 03:55:42 GMT

Project Description
A Linq provider for Amazon SimpleDB

No official release is available, but please feel free to download the latest source release and provide feedback.

UPDATED WIKI: Home

jetheredge — Wed, 23 Jan 2008 03:53:16 GMT

Project Description
A Linq provider for Amazon SimpleDB

Source code checked in

jetheredge — Wed, 23 Jan 2008 03:52:01 GMT

Source code checked in

jetheredge — Wed, 23 Jan 2008 03:29:37 GMT