JsonToObjectPropertyHandler

A property handler that maps the SQL Server json type into any property type via System.Text.Json.

A property handler that maps the SQL Server json type, which the database returns as a string, into a TObject property via JsonSerializer. Use it for the types that are not entities, such as collections and dictionaries.

This handler is compiled only for .NET 8 and later. It is not available on the netstandard2.0 target of the RepoDb package.

The conversion is the same as JsonToEntityPropertyHandler. The two classes differ only by the intent of the type argument.

Overview

Conversions

Usability

Bind the handler, closed over the property type, to the property that maps to a json column.

Attribute

public class Setting
{
    public int Id { get; set; }

    [Map("values"), PropertyHandler(typeof(JsonToObjectPropertyHandler<Dictionary<string, string>>))]
    public Dictionary<string, string> Values { get; set; }
}

Once bound, the library invokes the handler automatically when the property is read or written.

using (var connection = new SqlConnection(connectionString))
{
    connection.Insert(new Setting { Id = 1, Values = new Dictionary<string, string> { ["theme"] = "dark" } });
    var setting = connection.Query<Setting>(e => e.Id == 1).First();
    // setting.Values["theme"] is "dark"
}

Fluent Mapping

To configure via FluentMapper:

FluentMapper
    .Entity<Setting>()
    .PropertyHandler<JsonToObjectPropertyHandler<Dictionary<string, string>>>(e => e.Values);

Property Level Mapping

To configure via PropertyHandlerMapper:

PropertyHandlerMapper.Add<Setting, JsonToObjectPropertyHandler<Dictionary<string, string>>>(e => e.Values, new JsonToObjectPropertyHandler<Dictionary<string, string>>(), true);

Type Level Mapping

To apply the handler to every property of the type Dictionary<string, string>:

PropertyHandlerMapper.Add<Dictionary<string, string>, JsonToObjectPropertyHandler<Dictionary<string, string>>>(new JsonToObjectPropertyHandler<Dictionary<string, string>>(), true);

A type level mapping is process-wide: it is applied to every Dictionary<string, string> property of every entity and connection, not only to the intended column. Prefer the attribute, fluent or property level mapping unless every Dictionary<string, string> property maps to a json column.

See Also

• JsonToEntityPropertyHandler