Handlers · 2 min read

JsonToJsonDocumentPropertyHandler

A property handler that maps a database json column, such as the MySQL JSON type, into a JsonDocument property.

A property handler that maps a database json column (for example, the MySQL JSON type) into a JsonDocument property.

JsonDocument is IDisposable. The document created by this handler is owned by the entity, and it is the responsibility of the caller to dispose it. To avoid the disposal, use JsonToJsonElementPropertyHandler or JsonToJsonNodePropertyHandler.

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

Overview

Name	Description
Class	`JsonToJsonDocumentPropertyHandler`
Namespace	`RepoDb.PropertyHandlers`
Package	RepoDb
Implements	IPropertyHandler`<string, JsonDocument>`
Column type	A `json` column (for example, the MySQL `JSON` type), returned by the driver as a `string`
Property type	`JsonDocument`
Availability	Not available on the `netstandard2.0` target of the package; requires .NET 8 or later.

Conversions

Method	Direction	Description
Get	Database to property	Parses the JSON text into a `JsonDocument`. A `null` or an empty value is returned as `null`.
Set	Property to database	Converts the `JsonDocument` into its raw JSON text via `RootElement.GetRawText()`. A `null` value is written as `null`.

Usability

Bind the handler to the property that maps to a JSON column.

Attribute

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

    [Map("attributes"), PropertyHandler(typeof(JsonToJsonDocumentPropertyHandler))]
    public JsonDocument Attributes { get; set; }
}

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

using (var connection = new MySqlConnection(connectionString))
{
    var attributes = JsonDocument.Parse("{\"color\":\"red\"}");
    connection.Insert(new Product { Id = 1, Attributes = attributes });

    var product = connection.Query<Product>(e => e.Id == 1).First();
    var color = product.Attributes.RootElement.GetProperty("color").GetString();
    product.Attributes.Dispose(); // the caller owns the document
}

Fluent Mapping

To configure via FluentMapper:

FluentMapper
    .Entity<Product>()
    .PropertyHandler<JsonToJsonDocumentPropertyHandler>(e => e.Attributes);

Property Level Mapping

To configure via PropertyHandlerMapper:

PropertyHandlerMapper.Add<Product, JsonToJsonDocumentPropertyHandler>(e => e.Attributes, new JsonToJsonDocumentPropertyHandler(), true);

Type Level Mapping

To apply the handler to every property of the type JsonDocument:

PropertyHandlerMapper.Add<JsonDocument, JsonToJsonDocumentPropertyHandler>(new JsonToJsonDocumentPropertyHandler(), true);