Count records in database

I have the code below which does work, but I need to add further functionality to it. The functionality I want to add to it is the text I have commented in the code below.

Dim objSQLConnection As SqlConnection
Dim objSQLCommand As SqlCommand

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs)
    Dim intID As Integer = CType(Request.Form("ID"), Integer)
    Dim strHeading As String = CType(Request.Form("Heading"), String)
    Dim intState As Integer = CType(Request.Form("State"), Integer)
    Dim strUser As String = CType(Request.Form("User"), String)

    objSQLConnection = New 开发者_StackOverflow中文版SqlConnection(System.Configuration.ConfigurationManager.AppSettings("connString"))

    ''#count if records with this user already exist in the database below

    If intState = 1 Then
        objSQLCommand = New SqlCommand("insert into table1 (id, heading, user) values (@intID, @strHeading, @strUser)", objSQLConnection)

        objSQLCommand.Parameters.Add("@intID", SqlDbType.Int, 4).Value = intID
        objSQLCommand.Parameters.Add("@strHeading", SqlDbType.VarChar, 255).Value = strHeading
        objSQLCommand.Parameters.Add("@strUser", SqlDbType.VarChar, 3).Value = strUser
    ElseIf intState = 0 Then
        objSQLCommand = New SqlCommand("delete from table1 where id = @intID and user = @strUser", objSQLConnection)

        objSQLCommand.Parameters.Add("@intID", SqlDbType.Int, 4).Value = intID
        objSQLCommand.Parameters.Add("@strUser", SqlDbType.VarChar, 3).Value = strUser
    End If

    objSQLCommand.Connection.Open()
    objSQLCommand.ExecuteNonQuery()
    objSQLCommand.Connection.Close()
End

Before the if statement, I want to find out if the database already has records with the username in the strUser variable. What is the best way to go about doing this?

I'm not going to do all of this for you but a simple way to check the count is store the result of a stored procedure (SQL Server) into a SqlDataReader and check if the count > 0 or if HasRows = True.

With (myObjectCommand)
    .Parameters.Add("@strUser", SqlDbType.Varchar, 3).Value = myUser
    myReader = .ExecuteReader
End With

if myReader.HasRows
    return true ?
end if

Simple enough. Just do ExecuteScalar on the database with a query like "Select field1 from table where username = @username" and pass the strUser into the query object. Then save the scalar result into a variable (result). Then you can do if result is <> "", do such and such.