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…

Microsoft Access File Extensions

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…

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 Not all controls have a ControlSource property and thus can fail to run. A…

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…

Hardware Recommendations For Running Access

Hardware matters. Invest in a faster PC and your Microsoft Access databases will run faster. Be alert for sellers packaging fast processors with minimal memory and a slow hard drive to keep prices low. Look at all aspects of the purchase when database speed is a priority. A faster hard drive is worth the investment…

Access IIf() function to SQL Server equivalent

What is the SQL Server equivalent to Access IIf() function? Access SQL IIf([ResultValue]>=1, [Result Value], Null) SQL Server CASE WHEN [Result Value]>=1 THEN [Result Value] ELSE NULL END

Self-documenting code

Strong preference should be given to writing code that is self-documenting. A common approach is to write a lot of comments, but the problem with comments are twofold: It actually can harm the readability because it adds to the overall length of code to read and understand. It must be correct or it can end…

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 UPDATE query to SQL Server

How do I convert an Access UPDATE query to SQL Server? Access SQL UPDATE Cars INNER JOIN UpdateList ON Cars.Parts = UpdateList.Parts SET Cars.Price = [Updatelist].[price] SQL Server UPDATE Cars SET Cars.Price = [Updatelist].[price] FROM Cars INNER JOIN UpdateList ON Cars.Parts = UpdateList.Parts