Microsoft Access saves information under the following file formats: File Format Extension Access Project (2007, 2010) .adp Access Blank Project Template (2007, 2010) .adn Access Database (2007, 2010, 2013, 2016) .accdb Access Record-Locking Information (2007, 2010, 2013, 2016) laccdb Access Web App Reference .accdw Access Signed Packages .accdc Access Database, used for Add-ins .accda Access…
Designing a lookup table with logic
It is very common for us to embed some kind of logic based on a lookup table or in some cases, a column of a table. Because we have application logic connected to it, the code are fragile and subject to changes as the requirements develops. We want to avoid this situation where we might…
Minimizing stateful code
First we need to define what a state is. A state means that the object has variable(s) that may cause it to behave differently, depending on the content of the variables. As an example, the Forms collection is stateful:
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Forms("SomeForm").Visible = False |
This is legal code and will compile but we can’t be assured that this will…
ID vs Code
There are cases where a table’s primary key is referred to often in the code. In fact, it might have some special meanings in code. It is highly encouraged to avoid the use of IDENTITY or AutoNumber (or any auto-incrementing schema) for those keys because it is also usually desirable to create a VBA Enum…
Use TryGet pattern for transient values
A number of objects may have extra properties or something where it might not exist for all instances. A good example might be finding Controlsource property on an Access.Control variable:
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For Each ctl In Me.Controls Debug.Print ctl.ControlSource 'A potential error Next |
Not all controls have a ControlSource property and thus can fail to run. A common approach is to use OERN:
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For Each ctl In Me.Controls On Error Resume Next Debug.Print ctl.ControlSource 'A potential error On Error GoTo 0 Next |
This will work…
Access CDate() function to SQL Server equivalent
What is the SQL Server equivalent to Access CDate() function? Access SQL CDate([Event Timestamp]) SQL Server Equivalent cast([Event Timestamp] as datetime) convert(datetime, [Event Timestamp])
Access Web Apps to be retired
It was announced that Access Services is going to be retired. Details of the announcement may be found here: Updating the Access Services in SharePoint Roadmap. Additional timeline information along with possible methods for exporting your data out of an Access web app may be found here: Access web apps no longer supported. While these articles…
Prefer compile time errors over run time errors
In VBA, there are several features that allow us to do things that may not be checked at the compile time. In particular, it is possible to write several late-bound expressions which means that it can potentially contain run-time errors. One common misconception about late-binding is that it’s a matter of adding a reference and…
Module level variables
It is common to create a big wall of declaration in a module such as this:
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Private strCompanyName As String Private dteOrderDate As Date Private lngOrderID As Long Private objEmail As Object Private objOutlook As Object |
While the code will compile and work fine, the discoverability and naming of the module level variables does become difficult and unwieldy. To help cut down on this ambiguity, it is recommended to create a private user-defined type…
Pivoting a dynamic set
SQL Server does not allow for a dynamic set, which can be problematic if you need to pivot based on the data that comes from rows and you can have various values in the column. In general, you need a stored procedure and dynamic SQL in order to handle the dynamic pivots. This requires uses…





