If you are using the Database Connectivity Toolset or ADO, I highly recommend connecting to the database using the OLE DB provider for SQL Server. The ODBC driver is unable to write more than 8 kB of data at once.
I would suggest that you consider the Database Connectivity Toolset for LabVIEW. It is a simplified interfact to database programming and it uses SQL to communicate with them. Here is a link to NI's webpage which discusses the toolset.