Today I finally got down to the New, Changed, and Deprecated Features for Microsoft Dynamics AX 2012 e-book and the very first topic – Table relations – forced me to explore it a bit closer. The main difference is that relations aren’t defined on data types anymore, they’re defined on tables only. Nevertheless a data type can still be bound with a table by ReferenceTable property.
Relations on existing data types work also in AX2012, but it is recommended to move them on a table (it can be expected that they won’t be supported in the next version of AX). This conversion can be done using EDT Relation Migration Tool (I haven’t tried it yet).
There is another topic related to table relations: new properties on relations in AOT, which allows – for example – to define cardinality of a relation (1:1 etc.). Although many of these properties are not used by Axapta in any way, they definitely shouldn’t be ignored, because they make the data model understanding significantly easier. And also other application can have some use for them.
More information about these properties can be found on Vanya’s blog, or more specifically in a document linked from it.