SQL Column Does Not Exist Error - sql

Question

Okay, so basically I asked this little earlier today but we didn't get to the root of the problem and a lot of speculation was clouding the solutions. I have a program that currently needs to check a users inputed 'Gamer-Tag' from RegUserName.Text and compare that with Gamer-Tags stored on the SQL Table PersonsA which is in the Members_Details Database.
When the code is ran I receive the below error;
An unhandled exception of type 'System.ArgumentException' occurred in
System.Data.dll
Additional information: Column 'Gamer_Tag' does not belong to table
PersonsA.
However, Gamer-Tag IS in the Table; It's the second Column in the table. The Server is MS SQL Server and when I use the 'SQL Server Management Studio' I can clearly see the table & columns. From there all SQL Codes in relation to the Gamer_Tag column work flawlessly, so it's definitely in the database.
Here's the code which is called when a button is pressed. This code 'calls' the Function with the error.
Dim dbManager As New DatabaseManager() 'My Class Where The Functions Are
If dbManager.CheckGamerTagisMember(RegUserName.Text) Then
MsgBox("Gamer-Tag is NOT A Member.")
GoTo Ender
Else
MsgBox("Gamer-Tag is A Member.")
GoTo Ender
End If
And here's the Function which contains the Error;
Public Function CheckGamerTagisMember(ByVal gamertag As String) As Boolean
Connection = New SqlConnection("Data Source =" & My.Settings.ServerIP & ";Initial Catalog=Members_Details;Integrated Security=False;User=" & My.Settings.UserName & ";Password=*******;")
Connection.Open()
Dim gamertagDatSet As New DataSet()
usersDataAdapter.FillSchema(gamertagDatSet, SchemaType.Source, "PersonsA")
usersDataAdapter.Fill(gamertagDatSet, "PersonsA")
Dim table As DataTable = gamertagDatSet.Tables("PersonsA")
For i As Integer = 0 To table.Rows.Count - 1
Dim storedgamertag As String = table.Rows(i)("Gamer_Tag").ToString.ToString '<-------- ERROR
If (storedgamertag = gamertag) Then
gamertagDatSet.Dispose()
Connection.Close()
Return True
End If
Next
gamertagDatSet.Dispose()
Connection.Close()
Return False
End Function
What could cause this problem? I've checked obvious spelling and spacing, the firewall's off and the Column is without a doubt there. The function code was adapted from my SQL Login function, which worked without any issues, so I'm puzzled on why this isn't working.
Here's a screenshot from MS SQL Server Management Studio showing the PersonsA Table columns.
It's really getting frustrating now.

Answer 1

Some possible reasons:
Your user has actually been denied access to see the column. This can be accomplished via something as simple as:
DENY SELECT ON dbo.PersonsA(Gamer_Tag) TO your_user;
There is more than one PersonsA table, and the one you are accessing in your code is actually in a different schema than dbo. This is why you should always, always, always specify the schema when creating or referencing objects. Always. Read this post for more info.
Your code is connecting to a different server, a different database, or a different copy of the same database than Management Studio. (The latter can happen when using SQL Express and the User Instance/AttachDbFileName settings, which I can see that your code is not using, but I don't know if you are connecting to a user instance from Management Studio.)