In this blog we will use ExecuteScalar method to see
a record. Here we can find Min Marks, Max Marks, Avg Marks, Total Marks, Count
how many records, Max Mark Sid, Max Marks Sname of student table.
Imports System.Data
Imports System.Data.OleDb
Public Class
Form1
Dim ConnectionString As String =
System.Configuration.ConfigurationSettings.AppSettings("dsn")
Dim con As OleDbConnection = New
OleDbConnection(ConnectionString)
Dim com As OleDbCommand
Dim oledbda As OleDbDataAdapter
Dim ds As
DataSet
Dim str As String
Private Sub btnload_Click(ByVal sender As System.Object, ByVal
e As System.EventArgs) Handles
btnload.Click
Try
con.Open()
str = "select * from
student"
com = New
OleDbCommand(str, con)
oledbda = New
OleDbDataAdapter(com)
ds = New DataSet
oledbda.Fill(ds, "student")
DataGrid1.DataSource = ds
DataGrid1.DataMember = "student"
con.Close()
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
Private Sub btnmax_Click(ByVal sender As System.Object, ByVal
e As System.EventArgs) Handles
btnmax.Click
Try
con.Open()
str = "select
max(smarks)from student"
com = New
OleDbCommand(str, con)
Label1.Text = com.ExecuteScalar
con.Close()
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
Private Sub btnmin_Click(ByVal sender As System.Object, ByVal
e As System.EventArgs) Handles
btnmin.Click
Try
con.Open()
str = "select
min(smarks)from student"
com = New
OleDbCommand(str, con)
Label2.Text = com.ExecuteScalar
con.Close()
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
Private Sub btnavg_Click(ByVal sender As System.Object, ByVal
e As System.EventArgs) Handles
btnavg.Click
Try
con.Open()
str = "select
avg(smarks)from student"
com = New
OleDbCommand(str, con)
Label3.Text = com.ExecuteScalar
con.Close()
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
Private Sub btntotal_Click(ByVal sender As System.Object, ByVal
e As System.EventArgs) Handles
btntotal.Click
Try
con.Open()
str = "select
sum(smarks)from student"
com = New
OleDbCommand(str, con)
Label4.Text = com.ExecuteScalar
con.Close()
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
Private Sub btncount_Click(ByVal sender As System.Object, ByVal
e As System.EventArgs) Handles
btncount.Click
Try
con.Open()
str = "select
count(smarks)from student"
com = New
OleDbCommand(str, con)
Label5.Text = com.ExecuteScalar
con.Close()
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
Private Sub maxsid_Click(ByVal sender As System.Object, ByVal
e As System.EventArgs) Handles
maxsid.Click
Try
con.Open()
str = "select * from
student where smarks=(select max(smarks) from student)"
com = New
OleDbCommand(str, con)
Label6.Text = com.ExecuteScalar
con.Close()
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
Private Sub maxname_Click(ByVal sender As System.Object, ByVal
e As System.EventArgs) Handles
maxname.Click
Try
con.Open()
str = "select
max(smarks)from student"
com = New
OleDbCommand(str, con)
Label7.Text = com.ExecuteScalar
str = "select sname
from student where smarks=" & CInt(Label7.Text)
& ""
com = New
OleDbCommand(str, con)
Dim reader As OleDbDataReader = com.ExecuteReader
If reader.Read Then
Label7.Text = reader("sname")
End If
reader.Close()
con.Close()
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
End Class
Thanks for reading