From the Microsoft Dynamics 365 Business Central blogs: AL query objects, ReadState property; Extension uploads; Tell Me search feature

In this week's Microsoft Dynamics 365 Business Central blogs:

• BC 29: AL query objects and the new ReadState property
• BC 29: Every AL query you've written has been doing a dirty read
• How I recreated the extension upload experience
• Master the Tell Me search feature

AL query objects and the new ReadState property

Writing on his blog, Stefano Demiliani stated that a query object in AL is mainly used to read data. It also allows you to filter and group data, calculate totals or counts, and limit the number of rows returned. 

Demiliani wrote that by default, queries use the ReadUncommitted transaction isolation level. This means a query can read data even if another transaction involving that data has not finished. This can make queries faster because they don't take locks on the data they read or have to wait for other transactions to finish. However, he pointed out that the downside is that a query could return data that is later changed or removed if the other transaction fails and is rolled back.

In his post, Demiliani explained that beginning with Dynamics 365 Business Central 2026 release wave 2, version 29 and runtime 18, developers can choose the transaction isolation level for an AL query object using the new ReadState property.

Every AL query you've written has been doing a dirty read

Writing on his blog, Ammolh Saallvi stated that AL queries have always read data in a particular way, but most developers haven't had to think about how that worked because they didn't have another option.