September 2010
Intermediate to advanced
1704 pages
111h 8m
English
A highly specialized feature of SQL Server 2008, managed user-defined aggregates (UDAs) provide the capability to aggregate column data based on user-defined criteria built in to .NET code. You can now extend the (somewhat small) list of aggregate functions usable inside SQL Server to include those you custom-define.
If you’ve been following the examples in this chapter sequentially, at this point, you need to drop the sample table dbo.RegexTest to redeploy the assembly after creating the UDA example.
The implementation contract for a UDA requires the following:
• A static method called Init(), used to initialize any data fields in the struct, particularly the field that contains the aggregated ...