SQL behaves strange

[smktec]

Hi there,

I develop a database application where I communicate using VB 2010 epxress to MS Access 10 DB.
I can connect, download and display content of tables.
When I use the reader and sql statements like "select a,b from table" I receive data.
However, when I use the Oledbdataadapter it only works with sql statement like "select * from table". Es soon as I replace the "*" with detailed fields I do not recieve any data.

How could I resolve this?

[szlamany]

Welcome to the forum!

What are the actual field names you are trying to use?

[smktec]

Welcome to the forum!

What are the actual field names you are trying to use?

I have marked the line that results in no records with "<<<<< ".
Here is the code
Private Sub KundenID()
'Create the commands.
Dim queryString As String = "select * from Kundenliste"
'Dim queryString As String = "select Position from Kundenliste" <<<<<<<< no records are recieved
'Datenadapter aus der Datenbank füllen
Dim KundenAdapter As OleDb.OleDbDataAdapter = New OleDb.OleDbDataAdapter(queryString, connection)
KundenAdapter.MissingSchemaAction = MissingSchemaAction.AddWithKey

'DatenTable füllen
Dim Kundentabelle As New DataTable("Kundenliste")
KundenAdapter.Fill(Kundentabelle)
DG_Auftrag.DataSource = Kundentabelle ' fills DataGrid
'MsgBox(Kundentabelle.Rows(0).Item(0))
For i = 0 To Kundentabelle.Rows.Count - 1
CB_Firma.Items.Add(Kundentabelle.Rows(i).Item(1)) 'fills combobox
Next

End Sub

[szlamany]

Seems POSITION might be a reserved word

https://msdn.microsoft.com/en-us/library/ms189822.aspx

Try instead this syntax:

Dim queryString As String = "select [Position] from Kundenliste"

see if that works.

If it does I would recommend changing those fieldnames to words that are not reserved - you do not want to fight that battle.

[smktec]

Hi
I have now tried with this line:
Dim queryString As String = "select [Auftrags ID] from Kundenliste" '<<<<<<<< no records are recieved
but do still get no records downloaded.

[szlamany]

There cannot be a space in a field name so that syntax will certainly not work.

You said the field was POSITION?

And that you were trying to get ONE FIELD.

Be specific please.

[smktec]

Hi,

your comment helped I went through this and found out:
It was a stupid mistake that was carried through several programs: A wrong table was used that did not have those columns.

[TysonLPrice]

Hi,

your comment helped I went through this and found out:
It was a stupid mistake that was carried through several programs: A wrong table was used that did not have those columns.

That makes me wonder if you have error handling in your program. Something like that, select columns that do not exist, should have failed and could be trapped I would think.

[smktec]

you may be right.
I found this error at one place and it worked after I fixed it. But this was probably misleading. Later I found that VB crashed or ran into an error because an .exe file could not be copied into the debug folder. Only after deleting or waiting for some time I could restart (I put this into another thread). I also found that a combobox was called several times (by itself???). This could also have contributet. Now I have eliminated all these errors and it seems to work stable.