How to fix the Oracle error ORA-30756: cannot create column or table of type that contains a supertype attribute?

In this post, you’ll learn more about the Oracle ErrorORA-30756: cannot create column or table of type that contains a supertype attribute with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

ORA-30756: cannot create column or table of type that contains a supertype attribute

Reason for the Error ORA-30756: cannot create column or table of type that contains a supertype attribute

The user tried to create a column or table of an object type that contains a supertype attribute. This is not supported because it leads to infinite recursion in our current storage model. Note that creating a column of a type implies that we create columns corresponding to all subtype attributes as well.

How to fix the Error ORA-30756: cannot create column or table of type that contains a supertype attribute ?

You can fix this error in Oracle by following the below steps

Change the type definition to contain a supertype REF attribute instead of the supertype object attribute.