LINQ, Verbose WHERE Clause

Using LINQ, I updated the field Age of a Person object. When I looked at the generated SQL (from SQL Server Profiler), I saw the following.

Code:

exec sp_executesql N'UPDATE [dbo].[Persons]
SET [Age] = @p4
WHERE ([PersonId] = @p0) AND ([FirstName] = @p1) AND ([LastName] = @p2) AND ([Age] = @p3)',N'@p0 int,@p1 nvarchar(4),@p2 nvarchar(5),@p3 int,@p4 int',@p0=1,@p1=N'John',@p2=N'Smith',@p3=21,@p4=22

I was wondering why the WHERE clause has to include fields PersonId, FirstName, LastName, and Age when it could have just used the field PersonId. Is there a way to force LINQ to use primary key only?

I created database below.

Code:

CREATE TABLE dbo.Persons
(
	PersonId INT NOT NULL IDENTITY PRIMARY KEY
	, FirstName NVARCHAR(100) NOT NULL
	, LastName NVARCHAR(100) NULL
	, Age INT NOT NULL
)


INSERT INTO dbo.Persons
SELECT
	FirstName = 'John'
	, LastName = 'Smith'
	, Age = 21

Then, I created the .dbml by drag-and-dropping the database to my project.

And here's is my program.

Code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace LINQ
{
    class Program
    {
        static void Main(string[] args)
        {
            Entities.DataContext context = new Entities.DataContext();

            int personId = 1;
            Entities.Person person = context.Persons.SingleOrDefault(p => p.PersonId == personId);
            person.Age = 22;
            context.SubmitChanges();
        }
    }
}

perhaps this link will help.

I'm sorry. Did you forget to post the link because I don't see one?

Originally Posted by alphaoide

I'm sorry. Did you forget to post the link because I don't see one?

DOI!

LINQ Updates using all columns in the WHERE clause instead of Primary Key

sorry.

Thanks, the link really helped.