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:

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

This will work…

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…

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…

drag and drop in Access

Drag & Drop and Conditional Sorting in Microsoft Access

Drag and Drop In MS Access Doug was on a roll in January of 2004 when he wrote his article on drag and drop in MS Access. He tested it now using Access 2016 and it still works. This article shows you how to add drag-and-drop to your Access application using combinations of multi-value and…

IS NULL: Understanding and Using the Null Value in Microsoft Access

In Microsoft Access, a null value is a value that is not assigned or unknown. When working with databases, it’s important to understand how to use and identify null values in order to ensure accurate and efficient data management. The IS NULL operator is one of the most useful tools for working with null values…

Why does Excel have a problem when using code in Access?

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…

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:

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…

Access 2003

Microsoft Access 2003 Language Reference [Access 2003 VBA Language Reference]

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…

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…