get the latest record from the list .

Pakeeza

2y1.4kC#

Dear All I have this table as shown below

ID	Student_Name	Marks	Course_ID
1	ABC	78	1
2	HHH	88	3
3	ABC	89	1
4	ABC	99	1
5	CCC	67	2
6	HHH	76	3

From above table I would like to get the records I would like to take one record for each course ID but that records must be the latest one for that course ID like for course ID =1 the record I need to get should have ID =4 as this is the latest for course _ID 1 , same as for HHH I need to get row 6 and 6 is the latest record this is auto increament Id , and for CCC as there is only one record so I need to get 5th row, how to get this in linq query

6 Replies

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

Sachin Singh2y ago

Accepted answer

@Pakeeza it is even simpler in LINQ

var latestRecords = yourList
    .GroupBy(s => s.Course_ID)
    .Select(group => group.OrderByDescending(s => s.ID).First())
    .ToList();

Pakeeza2y ago
Dear both Uttam Chaturvedi,Sachin Singh the query Linq works as the SQL for this is provided by Uttam Chaturvedi so should I mark him even though you translated it into Linq there is no option to mark two as correct.
+1
Pakeeza2y ago
Uttam Chaturvedi can you share in LINQ
+1

Amit Mohanty2y ago

Check this:

List students = new List
{
    new Student { ID = 1, Student_Name = "ABC", Marks = 78, Course_ID = 1 },
    new Student { ID = 2, Student_Name = "HHH", Marks = 88, Course_ID = 3 },
    new Student { ID = 3, Student_Name = "ABC", Marks = 89, Course_ID = 1 },
    new Student { ID = 4, Student_Name = "ABC", Marks = 99, Course_ID = 1 },
    new Student { ID = 5, Student_Name = "CCC", Marks = 67, Course_ID = 2 },
    new Student { ID = 6, Student_Name = "HHH", Marks = 76, Course_ID = 3 }
};

var latestRecords = students
    .GroupBy(student => student.Course_ID)
    .Select(group => group.OrderByDescending(student => student.ID).First())
    .OrderBy(student => student.ID);

foreach (var record in latestRecords)
{
    Console.WriteLine($"ID: {record.ID}, Student_Name: {record.Student_Name}, Marks: {record.Marks}, Course_ID: {record.Course_ID}");
}

Pakeeza2y ago
I need this in Linq in SQL I did it thanks for the help
+1
Uttam Chaturvedi2y ago
Here you go with sql query to get latest records by id. Assuming your table name is student

SELECT * FROM dbo.student
WHERE id IN
(SELECT MAX(id) FROM dbo.student GROUP BY student_name)

Please accept answer, if you find it useful
0