Selecting or filtering value from DataSet

Suppose we have a District table having fields
District_Key
District_Name
District_StateKey
.....
.....

and have all the values in a dataset

DataSet dsState;

now we want to filter those value whoes state id is 4;
then we we can easily filter those value

DataRow[] dr = dsState.Tables[0].Select("State_Key=4");

Merging cells of a GridView

Suppose that we have a GridView data like this

Main Item	subItem	price
item1	s1	123
item1	s2	456
item 2	s1	878
item2	s2	456
item 2	s3	1231

And we want to create like this

Main Item	sub Item	price
item1	s1	123
	s2	456
item 2	s1	878
	s2	456
	s3	1231

Then we can get it by using the following code

protected void GridView1_DataBound(object sender, EventArgs e)
{
string text = "";
int count = 0;
Hashtable ht = new Hashtable();

// loop through all rows to get row counts
foreach (GridViewRow gvr in GridView1.Rows)
{
if (gvr.RowType == DataControlRowType.DataRow)
{
if (gvr.Cells[0].Text == text)
{
count++;
}
else
{
if (count > 0)
{
ht.Add(text, count);
}
text = gvr.Cells[0].Text;
count = 1;
}
}
}

if (count > 1)
{
ht.Add(text, count);
}


// loop through all rows again to set rowspan
text = "";
foreach (GridViewRow gvr in GridView1.Rows)
{
if (gvr.RowType == DataControlRowType.DataRow)
{
if (gvr.Cells[0].Text == text)
{
gvr.Cells.Remove(gvr.Cells[0]);
}
else
{
text = gvr.Cells[0].Text;
gvr.Cells[0].RowSpan = Convert.ToInt32(ht[text]);
}
}
}
}