Why is my reader stuck in infinite loop [closed] - sql

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Can anyone please explain why this is stuck in an infinite loop? I put this under a button and it worked fine. But when I put this in a class and instantiate the class, it gets stuck in an infinite loop. I assume it gets stuck in the loop because when I add breakpoints, it wont go further than inside the loop. It doesn't even get passed "End While", but if i put this code under a button click in ASP.NET it works just fine. What am I doing wrong?
Please don't criticize about "SQL injection" with the way I'm passing values to my database, because this isn't going to be a public thing and I'm well aware of that.
Imports System.Data
Imports System.Data.SqlClient
'Step 1: Select the device ID
Function SelectDevice(d As String, b As String, m As String, o As String) As String
' Try
'Connect to database
Dim xcitoDBConnection As SqlConnection
xcitoDBConnection = New SqlConnection("Data Source=NOTDISPLAYED;" + "Initial Catalog=NOTDISPLAYED;" + "Integrated Security=True")
Dim GetDeviceID As String = "SELECT DISTINCT(Identifier) FROM Support.Devices WHERE DeviceType='" & d & "' AND Brand = '" & b & "' AND Model = '" & m & "' AND OS = '" & o & "'"
Dim command As SqlCommand = New SqlCommand(GetDeviceID, xcitoDBConnection)
xcitoDBConnection.Open()
'command.ExecuteScalar()
Dim reader As SqlDataReader
reader = command.ExecuteReader(CommandBehavior.CloseConnection)
Dim GetID As String
While reader.Read()
GetID = reader("Identifier").ToString
Return GetID
End While
xcitoDBConnection.Close()
' Catch ex As ApplicationException
' ex.Source = ("Selection Error")
' Throw ex
' Finally
'End Try
End Function
End Class

Answer 1

write
reader = command.ExecuteReader()
instead of
reader = command.ExecuteReader(CommandBehavior.CloseConnection)
as you closed the connection at before return.
and return end of the function
follow this
Public Sub CreateCommand(ByVal queryString As String, _
ByVal connectionString As String)
Dim GetID As String
Using connection As New SqlConnection(connectionString)
connection.Open()
Dim command As New SqlCommand(queryString, connection)
Dim reader As SqlDataReader = command.ExecuteReader()
While reader.Read()
GetID = reader(0).ToString
End While
End Using
Return GetID
End Sub