Many people think that cascade update functionality is not available in AX. Since delete actions of ‘Cascade’ type are available to provide cascade delete functionality then why there is no cascade update. As usual Microsoft will not leave you in the middle of the sea. Cascade update is the default behavior of Ax if you create relationships between two tables via an EDT. Consider the following example.
A foreign key (one-to-many) relationship exists between AssetGroup and AssetTale. Field AssetGroupId in both tables are extended from AssetGroupId EDT. The relations node of AssetGroupId contians a relation b/w the two tables. Now if you update AssetGroupId in the AssetGroup Table, it will automatically update the related field in the AssetTable.