Support JSON properties with TPT/TPC inheritance mapping

[maumar]

Currently only TPH inheritance is supported.

[mahdishahbazi]

Hi @maumar, @AndriySvyryd and @ajcvickers . Do we have a timeline for this?

[roji]

@mahdishahbazi this is being considered for the 8.0 release, but it may or may not make it in.

[douglasg14b]

The docs for TPC strategy really need to list all these limitations as a big warning! It's quite painful to find out that feature x, y, and z is not supported when using TPC or hierarchies in general, AFTER designing around it.

I hope these features exist eventually, but for now guiding users away from the feature when they're just gonna cause themselves pain seems prudent.

[JasonLandbridge]

A workaround, or how it has traditionally been done:

public class BaseClassConfiguration : IEntityTypeConfiguration<BaseClass>
{
    public void Configure(EntityTypeBuilder<BaseClass> builder)
    {
        builder.UseTpcMappingStrategy();

        builder
            .Property(b => b.JsonProperty)
            .HasConversion(
                x => JsonSerializer.Serialize(x, JsonSerializerOptions.Default),
                x => JsonSerializer.Deserialize<SomeType>(x, JsonSerializerOptions.Default))
            .IsUnicode();
    }
}

This does mean you can't query and index the JSON values within but at least you can store it.

[onionhammer]

Every time I turn around there's another limitation I bumped into