In every implementation of Dynamics 365 for Finance & Operation,
there is need to add new fields in the core tables. With introduction of
extension framework, Microsoft provided a clean way to add new fields without over
layering the standard object hence making consumption of updates smooth.
However, Microsoft has introduced a best practice warning in
the compiler when there are more than 10 fields added on a table via extension.
The alternate recommended way is to create a new table and add a foreign key
relation to standard table. One of the benefit of moving fields to separate
tables is performance improvements. It makes sense because the performance cost
associated with the retrieval of the custom fields should only be incurred when
processes which needs these fields are executed.
This sounds good from database normalization perspective. But
when you are working in a business application, then the expectation is that
data in the custom table should be inserted, updated and deleted along with the
core table. In order to make developers life
easy there are maps – SysExtensionSerializerMap and SysExtensionSerializerExtensionMap
available out of the box.
These were available in previous versions of the product AX 2012.
If used smartly developers can save efforts and reduce
complexity to write custom logic of CRUD operations on the new table and in
fact provide more flexibility when we need to access the table buffer. Below are
key steps we should use when creating a new table to store custom fields:
Below is how a table, for illustration, should look. In this
example, I have created a table instead of adding fields via extension and have
only added one field.
Mapping properties should look like :
Below is how the relation properties should look like:
Define the index as alternate index and use it as
replacement key on the table properties
Index properties:
Table properties:
Once this mapping is added then developers don’t have to
worry about things like calling insert and update methods on the new table
whenever a record is created or updated in core table. This is how it works:
SysExtensionSerializerMap
has methods like postInsert(), postUpdate() and more as shown below.
postInsert() Inserts the packed extension table record after
the base table record is inserted, it uses SysExtensionSerializerFormRunHelper
class to perform the logic.
Most of the tables where insert method is overridden, call methods
of these maps as shown below
A nicely modeled data structure will enable developers to
focus on writing the business logic and leverage the platform capabilities.
Thanks for reading the blog. I still love the old school tag line to end the blog - happy DAXing J
