Option Compare Database
Option Explicit

Function sam0801()
    Randomize
    DoCmd.RunSQL ("update tmp set tmpstr=tmpstr+'" & Chr(Int(Rnd * 26 + 65)) & "'")
End Function

Function sam0802()
    If Len(DFirst("tmpstr", "tmp")) Mod 2 > 0 Then
        DoCmd.RunSQL ("update tmp set tmpstr=left(tmpstr,len(tmpstr)-1)")
    Else
        DoCmd.RunSQL ("update tmp set tmpstr=right(tmpstr,len(tmpstr)-1)")
    End If
End Function

Function sam0803()
    Dim dbs As Database
    Dim rst As Recordset
    Dim strSQL As String
    Dim i As Integer
    Set dbs = CurrentDb()
    strSQL = "SELECT * FROM [tmp];"
    Set rst = dbs.OpenRecordset(strSQL)
    rst.MoveFirst
    While Not rst.EOF
        rst.Edit
        rst!tmpstr = rst!tmpstr & "x"
        rst.Update
        rst.MoveNext
    Wend
    rst.Close
    dbs.Close
End Function