Ms-access – How to query for something like “last active” per column in Access

There is a solution with DAO:

Dim db As DAO.Database, tbl As DAO.TableDef
Dim f As DAO.Field
Set db = CurrentDb()

For Each tbl In db.TableDefs
    If tbl.Name = "Table1" Then
        For Each f In tbl.Fields
            If f.Attributes = 17 And f.Type = 4 Then    '(17 = dbAutoIncrField (16) + dbFixedField(1),  4 = dbLong)
                MsgBox ("Table1 idenity column: " & f.Name)
            End If
        Next f
    End If
Next tbl

This checks, if there is a column with Type = 4 [dbLong] and an Attributes value of 17 (16 [dbAutoIncrField] + 1 [dbFixedField]).

This worked fine for me so far.

It could be a mechanism within MS Access when it comes to the linked table. How ???

MSAccess sees a linked table and you issue this:

DELETE FROM [mytable];

This will not run over to SQL Server and do a deletion of all records in a single transaction. What MSAccess does is pick up every PRIMARY KEY and issues an individual DELETE FROM [mytable] WHERE pk = ???, probably as individual transactions (explains the delay before the confirm). I remembered this wonky behavior going back 15 years because I saw this happen when having linked tables to SQL Server, MySQL, and Oracle.

If this is still what MS Access does to a linked table, you are better off connecting to SQL Server via isql and issuing the DELETE on the server side, especially if there are a lot of rows to delete. At the very least, you should minimize executing bulk operations against SQL Server from MSAccess.

Although I have never worked with it, MSAccess can allow "pass through" queries where you issue a SQL Command and the ODBC Driver simply passes the query to the Server Side for parsing and execution rather that trying to parse and execute the SQL the "ODBC" way.

If things have changed over the years with linked tables, I'll leave it to the SQL Server community to address this if I am way off base.