How to map fields name in jsonb field to another name in object?-CodePudding

I use Postgres and I have DB with a table that looks like that

column - foo
type - jsonb
value - {"baz" : "test" }

Please notice that "baz" is not capitalized (pretty much this json document will be in a camelCase).

I have the code in C# (so the naming convention is Pascal Case)

public class Foo
{
     [Column(TypeName = "jsonb")]
     public BarData Bar { get; set; }
}

public class BarData
{
   // ??? What kind of annotation to put here
   public String Baz { get; set; }
}

I use entity framework npgsql to read/write to DB. Unfortunately, when npgsql read from DB, it won't populate Baz (because the naming convention doesn't match)

a) I tried to use [Column("baz")]. However, it's ignored (probably because it's not really a column, but a json tag)

b) I was considering naming the property "baz", but it just shifts a problem to another place in the code (where another mapping needs to be done).

As a result, I am looking whether I missed some way to do it case-insensitive or map the property to the name which comes from json.

CodePudding user response：

npgsql driver uses System.Text.Json for serializing json values. So all you need is to annotate your property with JsonPropertyName attribute.

public class BarData
{
   [JsonPropertyName("baz")]
   public String Baz { get; set; }
}

If your only concern is casing you can use JsonSerializerSettings.PropertyNamingPolicy

This is how you change serialization options as of version 6.0 :

var options = new JsonSerializerOptions
{
    // Customize based on needs...
};
NpgsqlConnection.GlobalTypeMapper.AddTypeResolverFactory(new JsonOverrideTypeHandlerResolverFactory(options));

Credits to this github answer

Also worth mentioning that the second workaround won't affect the query generation.