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…

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…

Access Web Apps

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…

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

Use properties instead of constant or magic numbers

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,…

Truthy and Falsy Values

“Truthy” and “Falsy” Values

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

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…

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)

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…

Use controls, not fields

Sometimes we need to use fields from a RecordSource that aren’t shown on the form. It is legal to reference them directly even if they don’t have a control. For example, we can have a form bound to a RecordSource like so:

And only display CompanyName in a textbox but not show the CompanyID….