How to properly use Seek in DAO database - ms-access

Question

I'm trying to search for currently selected item in my listbox control on my table.
In my listbox control after update event, I have this code
Private Sub lst_MainList_AfterUpdate()
Dim theDB As DAO.Database
Dim theProposalsTable As DAO.Recordset
Set theDB = CurrentDb
Set theProposalsTable = theDB.OpenRecordset("tbl_PROPOSAL", dbOpenDynaset)
theSeeker theProposalsTable, Me.lst_PPpg_MainList.Value
End Sub
Then I have a sub on my Module1 with this code. I got this from an example code # https://msdn.microsoft.com/en-us/library/office/ff836416.aspx
Sub theSeeker(ByRef rstTemp As Recordset, intSeek As Integer)
Dim theBookmark As Variant
Dim theMessage As String
With rstTemp
' Store current record location.
theBookmark = .Bookmark
.Seek "=", intSeek
' If Seek method fails, notify user and return to the
' last current record.
If .NoMatch Then
theMessage = "Not found! Returning to current record." & vbCr & vbCr & "NoMatch = " & .NoMatch
MsgBox theMessage
.Bookmark = theBookmark
End If
End With
End Sub
I am getting Runtime Error 3251 Operation is not supported for this type of object.
When I hit Debug, it highlights .Seek "=", intSeek

Answer 1

In this point from the linked page ...
Locates the record in an indexed table-type Recordset object
... "table-type Recordset" means you must use dbOpenTable instead of dbOpenDynaset with OpenRecordset()
That point is critical. If you can't open the table with dbOpenTable, you can't use Seek. And dbOpenTable can only be used with native Access tables contained in the current database. It can not be used with any kind of linked table.
So if dbOpenTable is compatible with tbl_PROPOSAL, this change will eliminate the first error ...
'Set theProposalsTable = theDB.OpenRecordset("tbl_PROPOSAL", dbOpenDynaset)
Set theProposalsTable = theDB.OpenRecordset("tbl_PROPOSAL", dbOpenTable)
If that does work, the next error will be #3019, "Operation invalid without a current index." That happens because you must set the controlling index before calling Seek ...
With rstTemp
' Store current record location.
theBookmark = .Bookmark
' Set the index.
.Index = "PrimaryKey" '<- use your index name here
.Seek "=", intSeek
If you need to list the names of your table's indexes, you can examine its TableDef.Indexes collection. Here is an Immediate window example with a table in my database ...
set db = CurrentDb
for each idx in db.TableDefs("tblFoo").Indexes : ? idx.name : next
id
PrimaryKey

Answer 2

You can't use the Seek method on a linked table because you can't open linked tables as table-type Recordset objects...
However, you can use the Seek method if you use the OpenDatabase method to open the backend database.
So instead of:
Set theDB = CurrentDb()
Do this:
Set theDB = OpenDatabase("full path to backend database")
Set theProposalsTable = theDB.OpenRecordset("tbl_PROPOSAL", dbOpenTable)

Answer 3

Allow me to combine these two old answers. Yes, you get an error when opening a linked table as dbOpenTable because that is only supported on tables local to the DB object you are working on. Like David pointed out, you can open the linked backend as a DB object and use that.
I'm using a reliable table in my back-end called "Settings". If you don't have a reliable table you can use to pull the back end you can pass in the table name as an argument.
I'm storing the backend object once I have a handle on it so we can call against it rapidly throughout our code without recreating the object.
Private thisBEDB As Database
'#Description("This allows us to call directly against linked tables.")
Public Function thisBackend() As Database
' For MS-ACCESS table
If (thisBEDB Is Nothing) Then
With DBEngine
Set thisBEDB = .OpenDatabase(Mid(CurrentDB.TableDefs("Settings").Connect, 11), False, False, "")
End With
End If
Set thisBackend = thisBEDB
End Function
Now we can use the backend handle to make the code in your example work as expected.
Private Sub lst_MainList_AfterUpdate()
Dim theDB As DAO.Database
Dim theProposalsTable As DAO.Recordset
Set theDB = CurrentDb
Set theProposalsTable = thisBackend.OpenRecordset("tbl_PROPOSAL", dbOpenTable)
theSeeker theProposalsTable, Me.lst_PPpg_MainList.Value
End Sub
Sub theSeeker(ByRef rstTemp As Recordset, intSeek As Integer)
Dim theBookmark As Variant
Dim theMessage As String
With rstTemp
.Index = "PrimaryKey"
' Store current record location.
theBookmark = .Bookmark
.Seek "=", intSeek
' If Seek method fails, notify user and return to the
' last current record.
If .NoMatch Then
theMessage = "Not found! Returning to current record." & vbCr & vbCr & "NoMatch = " & .NoMatch
MsgBox theMessage
.Bookmark = theBookmark
End If
End With
End Sub