FilterMode = CheckBoxList generates incorrect SQL Server query

The issue appears to be when switching from FilterMode = "Advanced" to "CheckBoxList". When in "Advanced" mode, queries are produced with the correct NULL comparison syntax e.g. "CASE WHEN [c].[CountryID] IS NOT NULL" etc..

When using the CheckBoxList mode, the same query is produced using "CASE WHEN [c].[CountryID] <> NULL" which will always return false.

I have attached a step by step guide to reproducing this but in almost all instances, I have just accepted default settings. I can include the entire solution is required but it's very easy to reproduce.

Radzen Blazor Studio NULL comparison (324.1 KB)

I've tried our Sample database with null value for Orders -> UserName column and here is what I've got:

The query:

Here is the same for OrderDetails -> OrderId:

Hi Vladimir,
Thanks for responding. There are no NULL values in the table, this issue is the query that is generated for the filtered results, not the query to fetch the list of distinct values to show in the dropdown. If you look at the file I attached, you'll see the difference between the two queries. The Advanced Filter generates the correct query to fetch the filtered results with two selections made, but the 'same' filter using the CheckBoxList mode generates invalid SQL Server code as it generates the where clause with "[filteredcolum] <> NULL" instead of [filteredcolumn] IS NOT NULL.

I'm happy to do a screen share to demo the issue if that would help.

This is exactly what it was shown in my post. To provide further support on this issue we will need an application along with a database that demonstrates the problem. You can share it on