System.Web.UI.WebControls Namespace SqlDataSource Class
.NET Framework version 2.0
Sets or retrieves a user-defined key dependency that is linked to all data cache objects that are created by the data source control. All cache objects are explicitly expired when the key is expired.
| Inline |
<asp:SqlDataSource cachekeydependency = strKey ... > |
| Script |
SqlDataSource.CacheKeyDependency [ = strKey ] |
| strKey |
A key that identifies all cache objects created by the SqlDataSource. |
The property is read/write with no default value.
The SqlDataSource control supports data caching. While data is cached, the Select method retrieves data from the cache rather than from the underlying database. When the cache expires, the Select method retrieves data from the underlying database, and then caches the data again.
You can set the CacheKeyDependency property to create a dependency between all cache entries that are created by the SqlDataSource control and the key. You can programmatically expire all the cache entries at any time by expiring the key.
The SqlDataSource control can cache data only when in the DataSet mode. A NotSupportedException exception is thrown by the Select method, if the SqlDataSource control is set to the DataReader value and caching is also enabled.
A unique cache entry is created for every combination of the SelectCommand, ConnectionString, and SelectParameters proerties. Multiple SqlDataSource controls can use the same cache entries in scenarios where the controls load the same data from the same underlying database.
NOTE: When you are using client impersonation under Microsoft Windows authentication, the data is cached when the first user accesses the data. If another user requests the same data, the data is retrieved from the cache. The data is not retrieved by making another call to the database to verify the user's access to the data. If you expect more than one user to access the data, and you want each retrieval to the data to be verified by the security configurations for the database, do not use caching.
