How to retrieve only updated/new records since the last query in SQL?

Posted by William Choi on Stack Overflow See other posts from Stack Overflow or by William Choi
Published on 2010-12-23T08:40:45Z Indexed on 2010/12/23 8:53 UTC
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sql

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mysql

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tsql

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query-cache

Hi all,

I was asked to design a class for caching SQL query results. Calling the class' query method will query and cache the entire set of results at the first time; afterward, each subsequence query will retrieve only the updated portion, and will merge the result into the cache. If the class is required to be generic, i.e. NO knowledge about the db and the tables, do you have any idea? Is it possible, and how to retrieve only updated/new records since the last query?

Thanks! William

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