Number sequences in Dynamics 365 for Finance and Operations are used to generate specifically formatted numbers for record identification. These number sequences can be anything from voucher numbers or transaction identification numbers to customer or vendor accounts.
When developing custom functionality, often one of the tasks is to add a new number sequence to the system in order to support newly created tables. Adding a number sequence to the system is a two-step process. First, we create the number sequence itself; second, we start using it in some particular form or from the code.
D365 contains a list of NumberSeqApplicationModule derivative classes, which hold the number sequence's setup data for the specific module. These classes are read by the number sequence wizard, which detects existing number sequences and proposes to create the missing ones or newly added ones. The wizard is normally run as a part of the application initialization. It can also be rerun any time later when expanding the D365 functionality used, where a setup of additional number sequences is required. The wizard also has to be rerun if new custom number sequences are added to the system.
In this recipe, we will do the first step, that is, add a new number sequence to the system. In a standard application, the customer group number is not driven by any number sequence, so we will enhance this by creating it. The second step is explained later in the Using a number sequence handler recipe in Chapter 3, Working with Data in Forms.