System.DBNull error

kmcas10

I am receiving the following error in SQL Data Compare:

“Unable to cast object of type ‘System.DBNull’ to type ‘System.String’.

Does anyone know what this is or how to resolve it?

Chris Auckland

Thanks for your post.

This is normally a permissions issue.

The following SQL Compare article will explain the minimum permissions required for a comparison. It is also relavent to SQL Data Compare.

http://www.red-gate.com/supportcenter/C ... 000072.htm

I hope this helps.

prathima

Hi Chris,

Getting "The page requested is currently unavailable" when i tried to access this link http://www.red-gate.com/supportcenter/C ... 000072.htm"

Please provide the information.. I am getting the same error which is mentioned in the begining of this thread.

Chris Auckland

Hello,

You're right, that link is dead. This is the correct one:

http://www.red-gate.com/supportcenter/C ... QL_Compare\knowledgebase\SC_Permissions_Required.htm

I hope it helps.

prathima

Thanks for your quick reply Chris.

Actually the message I am getting is "Unable to cast object of type 'System.DBNull' to type 'System.String' during Registering databases when clicked on Compare Now.

FYI..I am using windows 7 OS, trying using hostnames with instance names this is what happening. But if i use IP address and SQL port number it is working fine.
Also it is working fine for my colleague who is using windows XP with host names with DB instance names for the same server.

So looks like some thing with windows 7 and red gate.