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…
When you use code to refer to Excel (and other programs as well) you need to be careful not to use any code that does not refer back to the instantiated application object. If you do so then you will find that Access instantiates another Excel (or other program) object which is not visible to…
VBA is quite very loose in what it deems “truthy” and “falsy”. For example, this procedure can produce surprising result:
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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…
I’ve been seeing more and more people having problems with the Unrecognized Database Format when creating or modifying an Access 2007 (accdb) format database in Access 2010 and then trying to open it again in Access 2007. The issue appears to be that Access 2010 does not have its own file format. When you add a…
A common programming mistake is to hard-code literals that corresponds to some property. That is particularly true with certain controls like tab controls & pages. The tab control exposes a Value property that indicates the current tab and the pages contains a PageIndex property that indicates its position in the tabs of the control. Thus,…
This reference contains conceptual overviews, programming tasks, samples, and references to guide you in developing solutions based on Microsoft Access. The reference contains the following sections: What’s New: Provides a list of new members by object and in alphabetical order. Concepts: Provides important concepts for developing custom Access solutions. Reference: Provides reference materials for the Access…
SSMA is used to migrate Access databases to SQL Server. This tool converts the Access database to an SQL Server or an SQL Azure database. It is not bundled with SQL Server – you will need to download and install this tool separately. Check your system requirements and view the installation procedure for SSMA. Preparing…
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…
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…
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…