Checking Value against database

[dan463va]

I have a program that uses a database to display information. The user is allowed to enter in information and save it to the database. How can I code something that will check what a user enters in a textbox with a value already in the database. If it is not in the database I will display a messagebox error. I've tried things like,

If txtTextbox.text <> objReader("SerialNumber") Then
 
MessageBox.Show
 
Return
 
End If

When the program runs it will crash out and not work properly.

 

[lingsn]

Assuming the objReader is a DataReader object, you have to make sure the DataReader still open and allow you to read the table column. If it is closed already, you have to do the DB query again.