<%@OutputCache VaryByParam="None" Duration="30"
SqlDependency="nwind-cache:Orders" %>
In web.config:
<system.web>
<caching>
<sqlCacheDependency enabled="true" pollTime="75000">
<databases>
<add name="nwind-cache"
connectionStringName="nwind"
pollTime="500" />
</databases>
</sqlCacheDependency>
</caching>
</system.web>