保存更改不保存

Question

有以下代码 -var employees = context.Employees.Where(e => e.Department.Name == "Engineering" || e.Department.Name == "Tool Design" || e.Department.Name == "Marketing" || e.Department.Name == "Information Services")                .OrderBy(e => e.FirstName)                .ThenBy(e => e.LastName)                .Select(e => new                {                    employeeFullInfo = $"{e.FirstName} {e.LastName} (${e.Salary * 12 / 100 + e.Salary:F2})"                   //firstName = e.FirstName,                   //lastName = e.LastName,                   //Salary = e.Salary * 12 / 100 + e.Salary                }).ToList(); context.SaveChanges();当我调用 saveChanges 方法时，数据库中什么也没发生，为什么？我希望每位员工加薪 12%，但在数据库中什么也没发生