Question Sql Table Adapter

[Th4x3]

He im creating a user login form where my users put in a nickname and the TableAdapter searches for the matching password and returns it to my program,

I made a little code to convert the tabulardata to an single string but when i use it i get a blank msgbox where the password should be...

This is the VB code:

        Dim DataConnection As TDTableAdapters.UsersTableAdapter = New TDTableAdapters.UsersTableAdapter
                
                Dim dt As System.Data.DataTable = DataConnection.GetLoginCredentials(Nickname.Text)

                For Each dr As System.Data.DataRow In dt.Rows
                    returnValue = dr("Password").ToString()
                Next

This is the SQL String used by the TableAdadapter

SELECT        Password
FROM            Users
WHERE        (Nickname LIKE @Nickname)

And when i used this SQL code because thought that the select values where the problem:

SELECT        Password, Nickname
FROM            Users
WHERE        (Nickname LIKE @Nickname)

I got this error code on the line: Dim dt As System.Data.DataTable = DataConnection.GetLoginCredentials(Nickname.Text)

Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints.

Did somebody encounter this problem before or just knows the solution to my problems?

Thanks in advance,
Milan v. Dijck

 

[kulrom]

If you are looking for the username as is then replace the LIKE with = ... otherwise if you want to see if e.g. username contains the parameter value change the sql code DO the following:

SELECT        Password, Nickname
FROM            Users
WHERE        (Nickname LIKE '%' + @Nickname + '%')

But i guess you need this change:

SELECT        Password, Nickname
FROM            Users
WHERE        (Nickname [B]=[/B] @Nickname)