Microsoft Access Blog

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:

For Each ctl In Me.Controls
  Debug.Print ctl.ControlSource 'A potential error
Next

For Each ctl In Me.Controls

Debug.Print ctl.ControlSource 'A potential error

Not all controls have a ControlSource property and thus can fail to run. A common approach is to use OERN:

For Each ctl In Me.Controls
  On Error Resume Next
  Debug.Print ctl.ControlSource 'A potential error
  On Error GoTo 0
Next

For Each ctl In Me.Controls

On Error Resume Next

Debug.Print ctl.ControlSource 'A potential error

On Error GoTo 0

This will work…

How to Display a Form Automatically when your Application Opens

This is a quick tip on how to automatically display a form when the user opens your Access Application. In addition to improving User Friendliness, your database design will also appear much more professional. The step by step instructions below will display the Switchboard form in figure 1 immediately upon the application opening. 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…

Using Custom Functions in Calculated Controls

Custom functions work the same way as MS Access built-in functions such as DateAdd, DatePart and DSum, but are instead created ourselves as database developers. We do this by creating a public function with the VBA programming language and save it inside a global module within the database. Today I am going to explain how custom functions can be…

Access InStr() function to SQL Server equivalent

What is the SQL Server equivalent to Access InStr() function? TargetField: String expression being searched SearchValue: String expression being sought StartPosition: Starting position for each search (optional) Access SQL InStr(TargetField, SearchValue) InStr(StartPosition, TargetField, SearchValue) SQL Server CHARINDEX(SearchValue, TargetField) CHARINDEX(SearchValue, TargetField, StartPosition)

Access 2007: Access Developer Extensions

The Microsoft Office Access 2007 Developer Extensions make it easy to deploy and manage solutions built using Microsoft Access. The Access 2007 Developer Extensions provide packaging and deployment tools and licensing and distribution agreements to make it easier for developers to bring solutions to market. Whether you are working in a small business or a…

Normalize all constraints’ & indices’ names

Constraints that are created by SSMA or by user via SSMS tend to have ugly names. Worse, auto-generated names are not stable across backups. Meaning if you restore a new database based on a copy of another database, the constraint names will change. That create huge problems during migrations because scripts that references constraint will…

“Truthy” and “Falsy” Values

VBA is quite very loose in what it deems “truthy” and “falsy”. For example, this procedure can produce surprising result:

If Me.MyBitField.Value = True Then
  'It is true
Else 
  'It is false
End If

If Me.MyBitField.Value = True Then

'It is true

Else

'It is false

End If

At the first glance, it seems expected that if the bit field is set to 1, it would succeed. But in fact, it wouldn’t because True is equivalent to -1, not 1. Unless we…