When an OleDb dataview is instantiated using (Select * from
MyAccess2000Table), why aren't the following datacolumn properties
accurately exposed:

Unique
AllowDBNull
DefaultValue

Dim Col As DataColumn
For Each Col In MyDataView.Table.Columns
Col.Unique
Col.AllowDBNull
Col.DefaultValue
Next

When I test these values at runtime, they do not reflect the state of my
Access table. Doesn't the JET4.0 Provider surface them to the DataView?

TIA

I hard coded the default value in my table building code.
(Don't know about anyone else.)

I use code like this to build my datatables.

Public Function GenMissingItemsTable() As DataTable
Dim dt As New DataTable("dtMissingItems")
Dim col As DataColumn
With dt.Columns
col = .Add("itemno", GetType(String))
col.MaxLength = 25
col.AllowDBNull = False
col = .Add("descr1", GetType(String))
col.MaxLength = 60
col.AllowDBNull = False
col = .Add("uom", GetType(String))
col.MaxLength = 3
col.AllowDBNull = False
End With
dt.PrimaryKey = New DataColumn() {dt.Columns("itemno")}

Return dt
End Function

--
Joe Fallon



<(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Thanks for the code snippet, Joe. But I'm not out of the woods yet. The
> FillSchema() method doesn't configure the DefaultValue property.
> So how do I get the important default value? Or even find out if there
> is one?
>
> I must allow the record to be written to the row with a blank column
> value, even if that column has AllowDBNull = False, when the column has
> a default value. But I cannot find out by examining the schema if there
> is a default value set for the column.
>
> Is everyone hard-coding default values into the front-end? That would be
> a maintenance problem if the default-value should change.
>
> Andi
>
> > Unique
> > AllowDBNull
> > DefaultValue
> >
> > Dim Col As DataColumn
> > For Each Col In MyDataView.Table.Columns
> > Col.Unique
> > Col.AllowDBNull
> > Col.DefaultValue
> > Next
>
>
> In article <#(E-Mail Removed)>, jfallon1
> @nospamtwcny.rr.com says...
> > [snip important stuff]
> >Public Sub GetSchema(ByRef dt As DataTable, _
> > ByVal strSQL As String, _
> > ByVal DBtype As String)
> > 'retrieve structure information into a datatable using the FillSchema
> > ' method of a DataAdapter object
> > ...<snip>
> > ElseIf DBtype = "OLEDB" Then
> > Dim cnn As New OleDbConnection(mConnStr)
> > Try
> > cnn.Open()
> > 'KB309488 - the Object array is for filtering the returned
data
> > (only TABLEs are returned not Views, etc.)
> > dt = cnn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, New
Object()
> > {Nothing, Nothing, Nothing, "TABLE"})
> > Finally
> > cnn.Close()
> > End Try
> > End If
> > End Sub
> >
> >