RESEED Identity Columns of All Tables

You can RESEED Identity Columns of all tables by using sp_MSForEachTable to loop through all the tables and executing the DBCC CHECKIDENT command if the specific table has an identity column:

EXEC sp_MSForEachTable '  
  
IF OBJECTPROPERTY(object_id(''?''), ''TableHasIdentity'') = 1  
  
DBCC CHECKIDENT (''?'', RESEED, 0)