Setting a field to null in SQL Server Enterprise Manager

We always end up in a situation where we need to update a value directly in the recordset and set it to null. E,g. when we are dealing with DateTime fields and wish to set the field to null. If you just leave the field blank and try navigating to the next row, SQL Server throws an error.

To explicitly set a value to null, click on the field in the resultset and type CTRL-0 (zero). This sets the field to null.
In SQL Server 2005 Management Studio, do not forget to click on Execute button to save the edits.

Changing Bitmap on BaseCommands/Tools at runtime

A common scenario that ArcObjects developers come across is creating a button or tool in ArcMap whose image changes when clicked.

Example: Say you wish to create a “LogOn” button whose bitmap needs to change to “LogOff” bitmap once the user has logged in.

Just setting base.m_bitmap to the new bitmap does not update the bitmap in ArcMap. Instead you need to use the BaseCommand.UpdateBitmap method.

Per ESRI .Net documentation:
UpdateBitmap changes the Bitmap for the command. Call this method to update the icon used for the command at runtime, after the command has already been instantiated.

IWorkspaceFactorySchemaCache

When working with bulk editing or editing operations that might cause performance hits, try using IWorkspaceFactorySchemaCache and enable schema caching. This is supposed to improve the performance. Some people have reported improved performance (3 times) on even DifferenceCursors when enabling schema cache.