Handlers · 2 min read

JsonToJsonElementPropertyHandler

A property handler that maps the SQL Server json type into a JsonElement property.

A property handler that maps the SQL Server json type, which the database returns as a string, into a JsonElement property.

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	`JsonToJsonElementPropertyHandler`
Namespace	`RepoDb.PropertyHandlers`
Package	RepoDb
Implements	IPropertyHandler`<string, JsonElement>`
Column type	The SQL Server `json` type, returned by the database as a `string`
Property type	`JsonElement`
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 and returns a clone of the root element, which is independent of the parsed document and does not need to be disposed. A `null` or an empty value is returned as `default(JsonElement)`, whose `ValueKind` is `Undefined`.
Set	Property to database	Converts the `JsonElement` into its raw JSON text via `GetRawText()`. An `Undefined` element 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(JsonToJsonElementPropertyHandler))]
    public JsonElement Attributes { 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 Product { Id = 1, Attributes = JsonDocument.Parse("{\"color\":\"red\"}").RootElement.Clone() });

    var product = connection.Query<Product>(e => e.Id == 1).First();
    var color = product.Attributes.GetProperty("color").GetString();
}

Fluent Mapping

To configure via FluentMapper:

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

Property Level Mapping

To configure via PropertyHandlerMapper:

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

Type Level Mapping

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

PropertyHandlerMapper.Add<JsonElement, JsonToJsonElementPropertyHandler>(new JsonToJsonElementPropertyHandler(), true);