When synchronizing databases, you may configure Data Compare for SQL Server behavior for synchronization script execution in case of error.
If you want to have consistent data in any case, select the Use single transaction check box on the General tab of the Data Synchronization wizard. If this option was selected, the entire synchronization script is executed as one single transaction. In case of any error or synchronization cancelling, all changes are rolled back.
If you want, for example, debug the synchronization script, and you don’t want changes to be rolled back, clear the Use single transaction check box. In such case script is executed till the batch, containing errors. All changes made by the statements before the batch, which caused error, are applied to the database, so you may see which changes were applied.
To avoid errors when synchronizing data, pay attention to the Synchronization Warnings. Exclude database objects that can cause errors from the synchronization.