How to solve this error database looks to have been partially upgraded in CiviCRM
You would be able to successfully upgrade following these steps:


Empty the civicrm database
Restore civicrm database from the backup that you had created before performing upgrade
Temporarily remove the paths for custom PHP/template files if you have through: Administer->System settings->Directories
Try upgrading to version 4.7 again
Restore the custom files paths if point 3 was applied


Hope this fixes the issue.