This example shows you how to update multiple records in database table that satisfies given condition (where condition) in a single line by using LINQ query in entity framework.Example :
using (DBEntities db = new DBEntities())
db.tblTemp.Where(x => x.ProductID == parmProductID && x.IsActive == true).ToList().ForEach(x =>
x.IsActive = false; x.UpdatedTimeStamp = DateTime.Now;
In the above example all the records which contains given ProductID and IsActive "true" records will be updated with IsActive "false" and UpdatedTimeStamp with current DateTime.