You need an AL development sandbox for this recipe, but since we're still dealing with CAL objects in this recipe, you need to make sure it's a specific version. The easiest method is to use a Docker container and use the mcr.microsoft.com/businesscentral/onprem:14.0.29537.0 image to build it.

You also need to download the ch5-upgrading-data-from-cal-objects-start.zip file from the ch5/3-upgrading-data-from-cal-objects folder in the GitHub repository link at the start of this chapter.

Here is the scenario we're working with:

• A customer has a modified on-premises database that has been upgraded from Dynamics NAV 2018 to Business Central. Their modifications have been merged to the new version. The customer now wants to convert their CAL modifications to AL.
• Their CAL modifications consist of the following tables and fields:
• A new Customer Level table.
• New fields added to the Customer table, including Level Code (Code[20], in relation to Customer Level) and Classification (Text[10]).
• In addition to converting their solution to AL, the customer would also like the Classification field to now point to a new Classification table so that they can perform more consistent reporting and analysis. They also want to change the field from a Text[10] field to a Code[20] field.

This recipe starts after the following has happened:

• The modified CAL objects have been exported and converted to AL.
• All non-table modifications have been removed from the CAL objects.
• After conversion, the modified CAL objects and fields have been renamed to add TMP to the end of each name (for example, Customer Level TMP).