System.InvalidOperationException when trying to execute SqlDataReader

Question

I would like to post my SQL results into a textlist in VB.net, I am selecting from 2 fields, UserName & Passwords

My query is:

USE fasttest2008;

SELECT [username],
       [password]
FROM   users;

I want it to post into tb_user & tb_pass

I have looked at another post on this site and managed to nearly get it, i feel that I am missing just one thing.

I am aware this code only posts the results into one field atm.

Dim sConnString As String = "Data Source=.\scuser;Initial Catalog=master;Integrated Security=True"
        Dim sText As String = String.Empty

        Using cn As New SqlConnection(sConnString)
            cn.Open()
            Dim cmd As New SqlClient.SqlCommand("use testdb select [username], [password] from users")
            Dim r As SqlDataReader = cmd.ExecuteReader()
            If Not r.HasRows Then Exit Sub

            Do While r.Read()
                sText = sText & ";" & r.GetString(0)
            Loop

            cn.Close()
        End Using

        lb_user.Text = sText

sText = r.GetString(0) & " - " & r.GetString(1) Passwords should not be stored as plaintext — Ňɏssa Pøngjǣrdenlarp
– Ňɏssa Pøngjǣrdenlarp, Commented Feb 12, 2016 at 14:49
@Plutonix The error I get is: An unhandled exception of type 'System.InvalidOperationException' occurred in System.Data.dll Additional information: ExecuteReader: Connection property has not been initialized. — SamCramphorn
– SamCramphorn, Commented Feb 12, 2016 at 14:50
Note that your title has nothing to do with a connection problem, the post doesnt mention an error and asks about something completely different. — Ňɏssa Pøngjǣrdenlarp
– Ňɏssa Pøngjǣrdenlarp, Commented Feb 12, 2016 at 15:02

User2012384 · Accepted Answer · 2016-02-12 15:00:26Z

3

Try modify the Connection to this:

Dim cmd As New SqlClient.SqlCommand("use testdb select [username], [password] from users", cn);

You have to associate the cn to cmd

As in the comment, you said the query isn't returning anything, so try removing the use testdb, and try running it in the Database server, see if it returns anything

edited Feb 12, 2016 at 15:00

answered Feb 12, 2016 at 14:54

User2012384

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3 Comments

SamCramphorn Over a year ago

Edit: Thanks, | This now goes through, however it doesn't return my results.

SamCramphorn Over a year ago

I used a breakpoint and it was contained in sText so I know it is their.

User2012384 Over a year ago

So you will have to find out when the sText is cleared

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