Select a few rows in a DataSet

  • Thread starter Thread starter Diego F.
  • Start date Start date
D

Diego F.

Hi, I'm trying to select the last 3 items from a database to show them. I'm
writing a method that returns the rows in a dataSet. The method is:
public DataSet Last3()

I added a new data field to my database, so I can order the rows and the
first 3 are the newest.

SELECT * FROM Table ORDER BY Date DESC

I fill a DataSet with all the rows, but I don't know how to select just the
first 3 and return them in the dataset.

Regards,

Diego F.
 
Hi Diego,

I do not what you want to do with it,

Using VB it can be.

dim dr1 as datarow =dataset.tables(0).rows(0)
dim dr2 as datarow =dataset.tables(0).rows(1)
dim dr3 as datarow =dataset.tables(0).rows(2)

Than you have the first 3 datarows

I hope this helps?

Cor
 
Thanks, I'm trying with that. How can I add the DataRows to a new DataSet?
I'm getting errors, something like "the datarow already belongs to other
datatable".

Regards,

Diego F.
 
Hi Diego,

Use DataTable.NewRow() method to obtain new row instance.
After you populate it, use DataTable.Rows.Add(yourNewRow)
 
Hi Diego,

Another approach watch typos just rougly typed.
\\\
dim dsnew as new dataset
dsnew = dsold.clone
for i as integer = 0 to 2
dim dr as datarow = dsold.tables(0).newrow
for y as integer = 0 to dsold.tables(0).columns.count - 1
dr(y) = dsold.tables(0).rows(i)y
next
dsnew.tables(0).rows.add(dr)
next
///

I hope this helps,

Cor
 
I solved it with the Fill method, using da.Fill(ds,0,3,"Table") instead of
da.Fill(ds), so I get the first three records.

--

Regards,

Diego F.

Miha Markic said:
Hi Diego,

Use DataTable.NewRow() method to obtain new row instance.
After you populate it, use DataTable.Rows.Add(yourNewRow)

--
Miha Markic [MVP C#] - RightHand .NET consulting & software development
miha at rthand com
www.rthand.com

Diego F. said:
Thanks, I'm trying with that. How can I add the DataRows to a new DataSet?
I'm getting errors, something like "the datarow already belongs to other
datatable".

Regards,

Diego F.
Click to expand...
Click to expand...
 
Hi Diego,

Greath, that is of course better, I never thought to look at that, there are
so much overloaded functions from the Fill (the page where this is on is as
far as I can see even not complete).

But now I do not forget it also.

Cor
 
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