Table inheritance in Dynamics AX 2012

Microsoft Dynamics AX 2012 supports table level inheritance.
A table can extend from another table if its SupportInheritance property is set to Yes. Otherwise the table cannot extend from another table.

When a table A is created:

• It is default inherited by Common table, this value cannot be seen in the table Extends property
• When a variable (or buffer) of table A is declared, this variable inherits class of xRecrod by default

Cannot inherit from any other table

You need to set Extends property of a table to specify its parent table. When a table A inherits from table B:

• Table A will contain all the fields of table B but you cannot see them in AOT view
• When a variable (or buffer) is declared of table A, it will access all the methods of table B and methods available in xRecord class

Table has inherited from another table

Hope it helps !!!

System fields of tables in Dynamics AX

When we create table in Dynamics AX, we create fields in that table. Those fields are then created as columns in the SQL database. These are called Custom Fields.

The AX framework manages some fields by itself, these are called System Fields. Some of the system fields are automatically generated (with a table property value set to Always in below table) and some fields are created on the choice of the developer.

To create the desired system field on your table you need to set table's property according to the following table:

System field	Table property
RecId	Always
RecVersion	Always
DataAreaId	SaveDataPerCompany = Yes
CreatedBy	CreatedBy = Yes
CreatedDate	CreatedDate = Yes
CreatedTime	CreatedTime = Yes
CreateTransactionId	CreateTransactionId = Yes
ModifiedBy	ModifiedBy = Yes
ModifiedDate	ModifiedDate = Yes
ModifiedTime	ModifiedTime = Yes
ModifiedTransactionId	ModifiedTransactionId = Yes

Hope it helps !!!