Single @DiscriminatorColumn works fine. Column product_type gets filled with correct discriminator value:

However, when I introduce 2 more classes that inherit Book, hence another @DiscriminatorColumn, none of the contracts are honored. Neither product_type gets populated (remains null) nor do book_type.

CodePudding user response：

Having multiple disciminator columns on a single entity is not possible according to the documentation

The strategy and the discriminator column are only specified in the root of an entity class hierarchy or subhierarchy in which a different inheritance strategy is applied.