get data after union max and min sql statement - sql

Question

Is there any way to combine these sql statements in one statement:
Dim s As String =
"SELECT byu,MAX(atttime) AS attime FROM att
WHERE pno='" + DataGridView1.Rows(i).Cells(0).Value.ToString + "'
and attdate ='" + curdate + "' and atttime>='" + mxtime + "'
and atttime<='" + mxtime2 + "' "
Dim xmd As New SqlCommand(s, con)
Dim dr As SqlDataReader = xmd.ExecuteReader
If dr.Read Then
DataGridView1.Rows(i).Cells(7).Value = dr("attime")
DataGridView1.Rows(i).Cells(14).Value = dr("byu")
End If
dr.close
Dim s2 As String =
"SELECT byu, MIN(atttime) AS attime FROM att
WHERE pno='" + DataGridView1.Rows(i).Cells(0).Value.ToString + "'
and attdate ='" + curdate + "' and atttime>='" + mintime + "'
and atttime<='" + mintime2 + "' "
Dim xmd2 As New SqlCommand(s2, con)
Dim dr2 As SqlDataReader = xmd2.ExecuteReader
If dr2.Read Then
DataGridView1.Rows(i).Cells(4).Value = dr2("attime")
DataGridView1.Rows(i).Cells(15).Value = dr2("byu")
End If
dr2.Close()
the table att has data as:
pno attdate atttime byu
2 2015/01/02 07:05:02 0
2 2015/01/02 07:07:02 1
2 2015/01/02 18:08:11 0
2 2015/01/02 19:15:02 1
i was trying since morning and didn't come up with something, the problem that when i union the 2 sql statement i couldn't get the "byu" of MAX(atttime) and also the "byu" of MIN(atttime) via SqlDataReader. I almost red all the questions in the site that related to this and nothing worked for me so far.the result of above code is:
2 2015/01/02 07:05:02 0
2 2015/01/02 19:15:02 1
please help, thanks.

Answer 1

You can join you queries like this and execute them as a batch statement
Dim s As String =
"SELECT byu as byu1,MAX(atttime) AS attime1 FROM att
WHERE pno='" + DataGridView1.Rows(i).Cells(0).Value.ToString + "'
and attdate ='" + curdate + "' and atttime>='" + mxtime + "'
and atttime<='" + mxtime2 + "' group by byu ;" +
"SELECT byu as byu2,MIN(atttime) AS attime2 FROM att
WHERE pno='" + DataGridView1.Rows(i).Cells(0).Value.ToString + "'
and attdate ='" + curdate + "' and atttime>='" + mintime + "'
and atttime<='" + mintime2 + "' group by byu ;"
This is the only idea i dont know how many columns you are getting from database you have to set your cells() value respective of column order which you are getting from database
Dim xmd As New SqlCommand(s, con)
Dim dr As SqlDataReader = xmd.ExecuteReader
If dr.Read Then
DataGridView1.Rows(i).Cells(7).Value = dr("attime1")
DataGridView1.Rows(i).Cells(14).Value = dr("byu1")
DataGridView1.Rows(i).Cells(4).Value = dr("attime2")
DataGridView1.Rows(i).Cells(15).Value = dr("byu2")
End If