How to Update an item in a list by LINQ

List empList = new List
{
new Employee()
{
EmpNo=101,EmpName="Anil",
AllDepart=new List
{
new Department ()
{
DeptNo=1,Dname="Sales",Location="Vij"
}
},
DeptName="DEV",
AllSales=new List
{
new Sales ()
{
SName="jjj",Sloc="ban",
Orders=new List{
new Order (){Oid=200,OName="ebay"
}
}
}
},
Purchages=new List
{
new Purchage ()
{
Id=200,IName="Mobiles"
}
//new Department ()
{
DeptNo=2,Dname="DEv",Location="Gun"
},
//new Department ()
{
DeptNo=3,Dname="pro",Location="Ong"
}
}
}
};
}
public static class LinqUpdates
{
public static void Update(this IEnumerable source, Action action)
{
foreach (var item in source)
action(item);
}
}
}

Yes you can but you need to write the extension method for it. Dont worry, Troy Magennis had written it. I used that extension method. The link is

http://www.hookedonlinq.com/UpdateOperator.ashx

Please go through the code. If you need any other info, please let me know.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.Linq;
using System.IO;
using System.Threading;
using System.Data.SqlClient;
namespace PracticeConsole
{
class Program
{
static void Main(string[] args)
{
Student[] _arrStudents = new Student[]
{
new Student("AAA","1","A"),
new Student("BBB","2","B"),
new Student("CCC","3","C"),
new Student("DDD","4","D"),
new Student("EEE","5","E"),
new Student("FFF","6","F"),
new Student("GGG","7","G"),
new Student("HHH","8","H"),
new Student("III","9","I")
};
Console.WriteLine("Before update");
foreach (Student _student in _arrStudents)
{
Console.WriteLine(String.Format("{0},{1},{2}", _student.Name, _student.Standard, _student.Status));
}
var query = (from stud in _arrStudents
where stud.Name == "BBB"
select stud)
.Update(st => { st.Standard = "0"; st.Status = "X"; });
Console.WriteLine("After update");
foreach (Student _student in _arrStudents)
{
Console.WriteLine(String.Format("{0},{1},{2}",_student.Name,_student.Standard,_student.Status));
}
}
}
class Student
{
public string Name { get; set; }
public string Standard { get; set; }
public string Status { get; set; }
public Student(string name, string standard, string status)
{
this.Name = name;
this.Standard = standard;
this.Status = status;
}
}
public static class UpdateExtensions
{
public delegate void Func(TArg0 element);
public static int Update(this IEnumerable source, Func update)
{
if (source == null) throw new ArgumentNullException("source");
if (update == null) throw new ArgumentNullException("update");
if (typeof(TSource).IsValueType)
throw new NotSupportedException("value type elements are not supported by update.");
int count = 0;
foreach (TSource element in source)
{
update(element);
count++;
}
return count;
}
}
}

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

anil babu12y ago
1. List empList = new List
2. {
3. new Employee()
4. {
5. EmpNo=101,EmpName="Anil",
6. AllDepart=new List
7. {
8. new Department ()
9. {
10. DeptNo=1,Dname="Sales",Location="Vij"
11. }
12. },
13. DeptName="DEV",
14. AllSales=new List
15. {
16. new Sales ()
17. {
18. SName="jjj",Sloc="ban",
19. Orders=new List{
20. new Order (){Oid=200,OName="ebay"
21. }
22. }
23. }
24. },
25. Purchages=new List
26. {
27. new Purchage ()
28. {
29. Id=200,IName="Mobiles"
30. }
31. //new Department ()
32. {
33. DeptNo=2,Dname="DEv",Location="Gun"
34. },
35. //new Department ()
36. {
37. DeptNo=3,Dname="pro",Location="Ong"
38. }
39. }
40. }
41. };
42. }
44. public static class LinqUpdates
45. {
47. public static void Update(this IEnumerable source, Action action)
48. {
49. foreach (var item in source)
50. action(item);
51. }
53. }
54. }
I want to update the above list using the below methods how?

I am trying this way not possible

Method is
1. public void Update(Employee obj)
2. {
3. var list = loadList; loadList.Where(p => p.EmpNo == obj.EmpNo).Update();
4. }
how to modify my method?