Automatic Refresh of Linked tables

  • Thread starter Thread starter Jake
  • Start date Start date
J

Jake

How do I get a Linked table to automatically refresh
without having to manually open the Linked Table Manager,
select the table and then telling it to refresh? I'd
like to either schedule this or have it run automatically
when running a report.

Thanks.
 
There is no need to refresh a link unless you chane the credentials.
Are you doing that?

I typically run code to delete existing links and re-create them.
Over the years I have found this to be far more reliable than refreshing
links.
Lots of minor reasons for this.

============================

For example, here is how I do it for SQL Server:

I use this procedure to re-create links to SQL Server.
====================================================
For Jet re-linking code see:
http://www.mvps.org/access/tables/tbl0009.htm
====================================================
(This eliminates the need to re-name all the tables to strip out dbo_ and it
allows you to point to different versions of the same database easily.)
There is a local Access table (tblODBCTables) that contains the table names
I want to link to on the Server.
Note: the source table name needs the dbo. prefix which is in the code. The
linked table name usualy omits this. .

Public Sub LinkSQLServerTables(strDSN As String, strDatabase)
On Error GoTo Err_LinkSQLServerTables

Dim dbs As Database, rs As Recordset, tdfAccess As TableDef
Dim dbsODBC As Database, strConnect As String

If strDSN = "" Then
MsgBox "You must supply a DSN in order to link tables."
Exit Sub
Else
strConnect = "ODBC;DSN=" & strDSN & ";UID=User;PWD=password;DATABASE=" &
strDatabase & ";"
End If

SysCmd acSysCmdSetStatus, "Connecting to SQL Server..."

Call DeleteODBCTableNames

Set dbs = CurrentDb
Set rs = dbs.OpenRecordset("tblODBCTables")
Set dbsODBC = OpenDatabase("", False, False, strConnect)

Do While Not rs.EOF
Set tdfAccess = dbs.CreateTableDef(rs![LinkTablename], dbAttachSavePWD)
tdfAccess.Connect = dbsODBC.Connect
tdfAccess.SourceTableName = dbsODBC.TableDefs("dbo." &
rs![LinkTablename]).Name
dbs.TableDefs.Append tdfAccess
rs.MoveNext
Loop

rs.Close
Set rs = Nothing
Set dbsODBC = Nothing
Set dbs = Nothing

Exit_LinkSQLServerTables:
SysCmd acSysCmdClearStatus
Exit Sub

Err_LinkSQLServerTables:
MsgBox ("Error # " & Str(Err.Number) & " was generated by " & Err.Source
& Chr(13) & Err.Description)
Resume Exit_LinkSQLServerTables

End Sub


'This procedure deletes all linked ODBC table names in an mdb.
Public Sub DeleteODBCTableNames()
On Error GoTo Err_DeleteODBCTableNames

Dim dbs As Database, tdf As TableDef, I As Integer
Set dbs = CurrentDb
For I = dbs.TableDefs.Count - 1 To 0 Step -1
Set tdf = dbs.TableDefs(I)
If (tdf.Attributes And dbAttachedODBC) Then
dbs.TableDefs.Delete (tdf.Name)
End If
Next I

dbs.Close
Set dbs = Nothing

Exit_DeleteODBCTableNames:
Exit Sub

Err_DeleteODBCTableNames:
MsgBox ("Error # " & Str(Err.Number) & " was generated by " & Err.Source
& Chr(13) & Err.Description)
Resume Exit_DeleteODBCTableNames

End Sub
 
The problem I have is that without refreshing the link,
am I getting the newest data from the linked table?
Maybe I am not understanding the linking very well.

-----Original Message-----
There is no need to refresh a link unless you chane the credentials.
Are you doing that?

I typically run code to delete existing links and re- create them.
Over the years I have found this to be far more reliable than refreshing
links.
Lots of minor reasons for this.

============================

For example, here is how I do it for SQL Server:

I use this procedure to re-create links to SQL Server.
====================================================
For Jet re-linking code see:
http://www.mvps.org/access/tables/tbl0009.htm
====================================================
(This eliminates the need to re-name all the tables to strip out dbo_ and it
allows you to point to different versions of the same database easily.)
There is a local Access table (tblODBCTables) that contains the table names
I want to link to on the Server.
Note: the source table name needs the dbo. prefix which is in the code. The
linked table name usualy omits this. .

Public Sub LinkSQLServerTables(strDSN As String, strDatabase)
On Error GoTo Err_LinkSQLServerTables

Dim dbs As Database, rs As Recordset, tdfAccess As TableDef
Dim dbsODBC As Database, strConnect As String

If strDSN = "" Then
MsgBox "You must supply a DSN in order to link tables."
Exit Sub
Else
strConnect = "ODBC;DSN=" & strDSN
& ";UID=User;PWD=password;DATABASE=" &
strDatabase & ";"
End If

SysCmd acSysCmdSetStatus, "Connecting to SQL Server..."

Call DeleteODBCTableNames

Set dbs = CurrentDb
Set rs = dbs.OpenRecordset("tblODBCTables")
Set dbsODBC = OpenDatabase("", False, False, strConnect)

Do While Not rs.EOF
Set tdfAccess = dbs.CreateTableDef(rs![LinkTablename], dbAttachSavePWD)
tdfAccess.Connect = dbsODBC.Connect
tdfAccess.SourceTableName = dbsODBC.TableDefs("dbo." &
rs![LinkTablename]).Name
dbs.TableDefs.Append tdfAccess
rs.MoveNext
Loop

rs.Close
Set rs = Nothing
Set dbsODBC = Nothing
Set dbs = Nothing

Exit_LinkSQLServerTables:
SysCmd acSysCmdClearStatus
Exit Sub

Err_LinkSQLServerTables:
MsgBox ("Error # " & Str(Err.Number) & " was generated by " & Err.Source
& Chr(13) & Err.Description)
Resume Exit_LinkSQLServerTables

End Sub


'This procedure deletes all linked ODBC table names in an mdb.
Public Sub DeleteODBCTableNames()
On Error GoTo Err_DeleteODBCTableNames

Dim dbs As Database, tdf As TableDef, I As Integer
Set dbs = CurrentDb
For I = dbs.TableDefs.Count - 1 To 0 Step -1
Set tdf = dbs.TableDefs(I)
If (tdf.Attributes And dbAttachedODBC) Then
dbs.TableDefs.Delete (tdf.Name)
End If
Next I

dbs.Close
Set dbs = Nothing

Exit_DeleteODBCTableNames:
Exit Sub

Err_DeleteODBCTableNames:
MsgBox ("Error # " & Str(Err.Number) & " was generated by " & Err.Source
& Chr(13) & Err.Description)
Resume Exit_DeleteODBCTableNames

End Sub

--
Joe Fallon
Access MVP



How do I get a Linked table to automatically refresh
without having to manually open the Linked Table Manager,
select the table and then telling it to refresh? I'd
like to either schedule this or have it run automatically
when running a report.

Thanks.


.
 
Yes.
A linked table will you show you the latest data when you close and re-open
it.

So will a query against it.
--
Joe Fallon
Access MVP



Jake said:
The problem I have is that without refreshing the link,
am I getting the newest data from the linked table?
Maybe I am not understanding the linking very well.

-----Original Message-----
There is no need to refresh a link unless you chane the credentials.
Are you doing that?

I typically run code to delete existing links and re- create them.
Over the years I have found this to be far more reliable than refreshing
links.
Lots of minor reasons for this.

============================

For example, here is how I do it for SQL Server:

I use this procedure to re-create links to SQL Server.
====================================================
For Jet re-linking code see:
http://www.mvps.org/access/tables/tbl0009.htm
====================================================
(This eliminates the need to re-name all the tables to strip out dbo_ and it
allows you to point to different versions of the same database easily.)
There is a local Access table (tblODBCTables) that contains the table names
I want to link to on the Server.
Note: the source table name needs the dbo. prefix which is in the code. The
linked table name usualy omits this. .

Public Sub LinkSQLServerTables(strDSN As String, strDatabase)
On Error GoTo Err_LinkSQLServerTables

Dim dbs As Database, rs As Recordset, tdfAccess As TableDef
Dim dbsODBC As Database, strConnect As String

If strDSN = "" Then
MsgBox "You must supply a DSN in order to link tables."
Exit Sub
Else
strConnect = "ODBC;DSN=" & strDSN
& ";UID=User;PWD=password;DATABASE=" &
strDatabase & ";"
End If

SysCmd acSysCmdSetStatus, "Connecting to SQL Server..."

Call DeleteODBCTableNames

Set dbs = CurrentDb
Set rs = dbs.OpenRecordset("tblODBCTables")
Set dbsODBC = OpenDatabase("", False, False, strConnect)

Do While Not rs.EOF
Set tdfAccess = dbs.CreateTableDef(rs![LinkTablename], dbAttachSavePWD)
tdfAccess.Connect = dbsODBC.Connect
tdfAccess.SourceTableName = dbsODBC.TableDefs("dbo." &
rs![LinkTablename]).Name
dbs.TableDefs.Append tdfAccess
rs.MoveNext
Loop

rs.Close
Set rs = Nothing
Set dbsODBC = Nothing
Set dbs = Nothing

Exit_LinkSQLServerTables:
SysCmd acSysCmdClearStatus
Exit Sub

Err_LinkSQLServerTables:
MsgBox ("Error # " & Str(Err.Number) & " was generated by " & Err.Source
& Chr(13) & Err.Description)
Resume Exit_LinkSQLServerTables

End Sub


'This procedure deletes all linked ODBC table names in an mdb.
Public Sub DeleteODBCTableNames()
On Error GoTo Err_DeleteODBCTableNames

Dim dbs As Database, tdf As TableDef, I As Integer
Set dbs = CurrentDb
For I = dbs.TableDefs.Count - 1 To 0 Step -1
Set tdf = dbs.TableDefs(I)
If (tdf.Attributes And dbAttachedODBC) Then
dbs.TableDefs.Delete (tdf.Name)
End If
Next I

dbs.Close
Set dbs = Nothing

Exit_DeleteODBCTableNames:
Exit Sub

Err_DeleteODBCTableNames:
MsgBox ("Error # " & Str(Err.Number) & " was generated by " & Err.Source
& Chr(13) & Err.Description)
Resume Exit_DeleteODBCTableNames

End Sub

--
Joe Fallon
Access MVP



How do I get a Linked table to automatically refresh
without having to manually open the Linked Table Manager,
select the table and then telling it to refresh? I'd
like to either schedule this or have it run automatically
when running a report.

Thanks.


.
 
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