You can validate the data contained in your import file without actually importing the data into the program. The Validate data only option searches your import files for errors you may encounter during an import. You can also choose to create a report detailing all exceptions and errors the program found during the validation process. You can then clear up any potential problems before you start importing data into your database. Remember, once you start the import/update process, the only way to restore your database is by restoring it to a backup. Also, if you select this option, the Import Now button at the bottom right of the screen changes to Validate Now.
1. Open the import parameters
2. Select the General tab
3. In the What do you want to do? frame, select Validate data only checkbox under options
4. Go through each tab and select the appropriate options. When done, click Validate Now.