Accessing SQL database

I have written the code to access data from a database, but I wish to set up security - i.e. doesn't write to the db unless a particular method is called.

In this particular case, I have 2 methods that are ExecuteUpdate and ExecuteQuery. The second should not allow the user to update the database.

I've tried using the SQLSetConnectAttr funtion to set to read only, but the docs say that this may not block an attempted update. In fact, it doesn't.

Anybody know of another way to do this?

Thanks

HD