Support mapping multiple owned types to the same JSON column (sharing)

[AndriySvyryd]

No description provided.

[ajcvickers]

This is not easy, but would enable some interesting and useful scenarios--see #29456.

[codelovercc]

@ajcvickers Hi, I am so excited about this feature. Any news? Will this be supported in Entity Framework Core 8 (EF Core 8; EF8) ?

[ajcvickers]

This issue is in the Backlog milestone. This means that it is not planned for the next release (EF Core 8.0). We will re-assess the backlog following the this release and consider this item at that time. However, keep in mind that there are many other high priority features with which it will be competing for resources. Make sure to vote (👍) for this issue if it is important to you.

[joakimriedel]

Please keep on voting for this issue so it might get prioritized for v9! 👍

With TPH this would make for a very powerful storage of metadata for similar, yet different, entities. Now the database would get flooded with columns like MetadataJsonA, MetadataJsonB, MetadataJsonC for each entity in the hierarchy. Once this gets implemented however, I imagine it will be easy to consolidate all columns to a single MetadataJson column.

[uabarahona]

Keep voting people, this is definitely an important feature that actually opens many uses cases for json columns, does anyone know if there is a workaround?

[digitalsigi]

This would be an exiting thing! I a certain project we store audit data of other Tables in auditlog table as json string and in another column we store the table name. One for old valua one for new new value. The json string is generated is overriden SaveChanges methode, This works very very well and allows to even display the changed values.

However, reading this column back into object is currently painful and requires a rather long if / else sequence to create the typed object.

Hopefully there will be a more general solution to this.

[elementh]

This would be game changing, honestly!

[roji]

Note #27779, which is also about mapping multiple types to the same JSON document (or sub-document), but where the types are in a hierarchy - also via the use of a discriminator ($type). We may want to implement these two features together.

Note also that we already allow mapping unrelated entity types to the same container in Cosmos with a discriminator property (but not sub-documents).