How to display query results from SQL server in VB? - sql-server

Question

I am trying to display query results from SQL server in VB. I wrote following code, but not getting how to "Just display the results";
Public Function ConnectToSQL() As String
Dim con As New SqlConnection
Try
con.ConnectionString = "Data Source=(local);Initial Catalog=TestDatabase;Persist Security Info=True;User ID=sa;Password=afm"
Dim cmd As New SqlCommand("SELECT username FROM users WHERE username='user'", con)
con.Open()
Console.WriteLine("Connection Opened")
' Execute Query
Dim reader As SqlDataReader = cmd.ExecuteReader()
While reader.Read()
Console.WriteLine(String.Format("{0}, {1}", _
reader(0), reader(1)))
End While
Catch ex As Exception
MessageBox.Show("Error while connecting to SQL Server." & ex.Message)
Finally
con.Close() 'Whether there is error or not. Close the connection.
End Try
Return reader
End Function
Can any one guide? Thank you

Answer 1

I corrected a few things and now your function works fine for me:
Public Function ConnectToSQL() As String
Dim con As New SqlConnection
Dim reader As SqlDataReader
Try
con.ConnectionString = "Data Source=(local);Initial Catalog=TestDatabase;Persist Security Info=True;User ID=sa;Password=afm"
Dim cmd As New SqlCommand("SELECT username, WindowsLogin FROM users WHERE username='user'", con)
con.Open()
Console.WriteLine("Connection Opened")
' Execute Query '
reader = cmd.ExecuteReader()
While reader.Read()
Console.WriteLine(String.Format("{0}, {1}", _
reader(0), reader(1)))
'NOTE: (^^) You are trying to read 2 columns here, but you only '
' SELECT-ed one (username) originally... '
' , Also, you can call the columns by name(string), not just by number '
End While
Catch ex As Exception
MessageBox.Show("Error while connecting to SQL Server." & ex.Message)
Finally
con.Close() 'Whether there is error or not. Close the connection. '
End Try
'Return reader { note: reader is not valid after it is closed } '
Return "done"
End Function
Let me know if you have any questions.