How to migrate webparts from 2010 to sharepoint 2013
I have mouted datbase with my new site on sharepoint 2013 but when i open it it say something went wrong
Without further details I would say to check the logs with the correlation ID. It should be on the logs folder under the 15 hive.
For migration I would recommend this 3 articles:
Migrating the Database and Site Collection
Don't forget to check if the database was sucessfully updated in the central administration -> Upgrade and Migration -> Review database status.
Also if you have custom solutions check this before upgrading the database:
http://technet.microsoft.com/en-us/library/dn673579%28v=office.15%29.aspx
And don't forget that sharepoint 2013 has a 2010 mode so they should be deployed to the 14 hive also (check the first image on the link above for a good overview)
Finally, also because sharepoint 2013 has 2010 mode you have to take notice to point your control templates to the correct hive:
http://msdn.microsoft.com/en-us/library/office/dn296464%28v=office.15%29.aspx