Well, yes - you will.
Let me rip some code out so it's easier to see:
count = count + 1
If count = 1 Then
Form2.Label2.Text = reader(2).ToString
You loop through all rows to count them. So after the loop,
is guaranteed to not be looking at a row - because if it was then
would not have returned false!
isn't on a row, and if you try access row data, there isn't any there to look at! And you get an error as a result.
But that is extremely dangerous code, particularly so on a login form! Never concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Always use Parameterized queries instead.
When you concatenate strings, you cause problems because SQL receives commands like:
SELECT * FROM MyTable WHERE StreetAddress = 'Baker's Wood'
The quote the user added terminates the string as far as SQL is concerned and you get problems. But it could be worse. If I come along and type this instead: "x';DROP TABLE MyTable;--" Then SQL receives a very different command:
SELECT * FROM MyTable WHERE StreetAddress = 'x';DROP TABLE MyTable;
Which SQL sees as three separate commands:
SELECT * FROM MyTable WHERE StreetAddress = 'x';
A perfectly valid SELECT
DROP TABLE MyTable;
A perfectly valid "delete the table" command
And everything else is a comment.
So it does: selects any matching rows, deletes the table from the DB, and ignores anything else.
So ALWAYS use parameterized queries! Or be prepared to restore your DB from backup frequently. You do take backups regularly, don't you?
And that means you need to go through your whole app as a matter of priority and fix that throughout: leave just one and your database is at risk!
The other problem is the way you are handling passwords, which is both dangerous and (since GDPR) can mean you are liable for prosecution for negligent handling of user data if a EU citizen tries to use your system ...
Never store passwords in clear text - it is a major security risk. There is some information on how to do it here: Password Storage: How to do it.
] - the code is in C#, but it's pretty simple, and tehre are online converters if you can't cope: Code Converter C# to VB and VB to C# – Telerik