There are several old (around 2009) questions on SO addressing this issue, for example:
How do I update a Linq to SQL dbml file?
Just to confirm, is it still the case that VS2010 does not (and can not) automatically update LinqToSQL DBML files when a schema change occurs in the underlying database? So one must still either delete all tables from the existing DBML diagram and re-add, or use one of the 3rd party offerings to do the code generation, is this correct??
(If so, recommendations on the latest/greatest 3rd party tool, including price, would likely be helpful to others).
Correct. Entity Framework supports this though.
If you’re sticking to LINQ to SQL, this tool does what you want: http://www.huagati.com/dbmltools/