You should utilize the SqlCacheDependency
class for that, for example:
VIEW:
<%@ OutputCache Duration="3600" SqlDependency="Northwind:Employees" VaryByParam="none" %>
WEB.CONFIG:
<caching>
<sqlCacheDependency enabled = "true" pollTime = "60000" >
<databases>
<add name="northwind"
connectionStringName="Northwind"
pollTime="9000000"
/>
</databases>
</sqlCacheDependency>
</caching>
The above example shows an ASP.NET Web.config file that enables table-based dependencies on a SQL Server database table.