Skip to main content

Return top N rows from datatable

Normally to return top N rows we use an SQL statement similar to the one below

Select top N * from table

but How can we achieve the same thing in DataTable
I have seen many examples, using different methods. Most of the methods centered around the idea of creating new columns with automatic values increment and using them as index 

There is better method using LINQ 

public  DataTable GetTopNFromDataTable(int TopRowCount, DataTable dtSource)

            var dtTrec = from item in dtSource.AsEnumerable()
                         select item;
            var topN = dtTrec.Take(TopRowCount);
            DataTable dtNew = new DataTable();
            dtNew = dtSource.Clone();

            foreach (DataRow drrow in topN.ToArray())


            return dtNew;

var dtTrec - stores the item in datatable, Using the Take function of Linq the first N rows is filtered

            var topN = dtTrec.Take(TopRowCount);

Now how to retrieve the rows between N1 & N2, just use the skip function along with Take as shown below

public DataTable GetTopBetweenFromDataTable(int intFrom, int intTo, DataTable dtSource)

   var topN = dtTrec.Skip(intFrom).Take(intFrom);




Anonymous said…
Dim query = From c In dt.AsEnumerable _
Order By c.Field(Of Decimal)("list_order") Descending, _
c.Field(Of DateTime)("insert_date") Descending

Dim query1 = From c In query.Take(5).AsEnumerable
rptNews.DataSource = query1

Popular posts from this blog

SCRUM- Who should write a user story

Traditionally user stories (or requirements) were written by Business analysts. They used to prepare big documents after months of study. It was a herculean task. I used to get such UI/Functional specification documents. I have fixed a lot of bugs because I missed few text in such 1000 + pages document. This is not the only interesting part. Some of the requirements were so weird that I often wondered why I am creating the features which no one is going to use. If I had the option I would have recommended a better option. If the BA’s misunderstood some requirements & customers failed to correct those few words in the epic requirement then we will have a nice situation. In the agile world the story is different. Product Owners are primarily responsible for user stories. But can anyone else also contribute? Yes. Definitely yes In actual environment many users write user stories. The first requirement may come from end user. The PO, tech architect, scrum master, BA’s... anyone can up

What are the rules of scrum?

A relatively new person to scrum asked me this question last day. My answer to that person was yes. But really does the scrum have any rules? Scrum is a framework which helps us in developing software. It has very few rules and apart from those basic rules rest of them are guidelines like best practices. Some of the rules  The roles of Scrum • Scrum Master - • Product Owner • Feature Team The PDCA cycle (  )  frequent communication about risks (daily) • Plan – Sprint planning • Do – Actual engineering sprint – deliver a potential shippable code • Check – Sprint review • Act – Retrospective  The scrum guide @ will be a good guideline for teams/companies planning to start scrum. If you are following the recommendation in these then you are following scrum. Apart from these rest of

Product Backlog: Should you write everything in user story format?

I like user stories a lot. They help everyone talk the same language and results in a better product. User story alone does not constitute product requirement. User story is supposed to be a place holder for discussion which should happen between the team, Product Owner and the customer. This discussion result in a common understanding which along with the user story content is the product requirement. This format captures the essence of requirement without confusing the readers User Story is only one of the many different ways in which requirements can be represented. This is not mandatory in any Agile “process”. But many have made this mandatory. I have seen many spending countless hours trying to write the requirements in user story format when they could have easily written that in simple one-line sentence in few minutes.   I have seen team members refusing to even discuss the requirement until product owner rewrote the requirement in user story format. Once I