Return a Subset of Data from a Table

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The ability to page in SQL Server is one of those things that everyone wants, but can't quite seem to get from Microsoft. Many ideas have been posted, each claiming to be _the_ way to do it. In the spirit of mine is better than yours, I've implemented my own paging scheme.

A feature that is in the upcoming version of SQL Server is the ability to supply a variable to the TOP keyword. Well, as it turns out, this functionality does exist in SQL Server 2000. The only difference is the syntax. To limit the number of rows returned from a query based on a variable is to use SET ROWCOUNT @Foo. Don't forget, however, to reverse that after the query by setting ROWCOUNT to 0.

The principle of which this works is that I return all of the primary keys in a table into a table datatype up to and including the record that i want to start at. Then I grab that value by selecting the TOP 1 from that temp table, ordering by the value, descending. Now I have the starting primary key value.

At this point, it's a matter of looping through the records, row by row until I have filled my cache table with a single page's worth of data. Once that is complete, I return the contents of the cache table. In addition, in the form of an OUTPUT param, I return the total number of rows in the table. I have this value as a result of a sanity check that stops the proc if we are requesting a page of data that is past the end of the table.

I hope this sproc finds you well.

Total article views: 284 | Views in the last 30 days: 15