EF Core 7.0 Json 列类型和实体配置

Question

I would like to arrange new feature which is Json column types in EF Core 7.0 but i am not sure how to make entity configuration ( https://www.npgsql.org/efcore/mapping/json.html?tabs=fluent-api%2Cpoco )

For example, I have a class:

public class Entity
{
    public Guid Id { get; set; }
    public bool Deleted { get; set; }
    public string Name { get; set; }
    public DateTime Date { get; set; }
}

I would like to create table which looks like this: Columns: Id (Guid), Deleted (bool), Data (json string)

Data in json column should look like:

{
    "Id": "00000000-0000-0000-0000-000000000000",
    "Deleted": false,
    "Name": "Example name",
    "Date": "2022-12-20T22:07:17Z"
}

How can i configure entity to get expected result?

Answer 1

You can configure your models like this,

DataEntity.cs

public class DataEntity
{
    public Guid Id { get; set; }
    public bool Deleted { get; set; }
    public string Name { get; set; }
    public DateTime Date { get; set; }
}

OwnerEntity.cs

public class OwnerEntity
{
    public Guid Id { get; set; }
    public bool Deleted { get; set; }
    public DataEntity Data { get; set; }
}

Now the key part is in your model configs,

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<OwnerEntity>().OwnsOne(
        owner => owner.Data, ownedNavigationBuilder =>
        {
            ownedNavigationBuilder.ToJson();
        });
}

After you run the Add-Migration command, you should see the migration script like this,

migrationBuilder.CreateTable(
    name: "OwnerEntities",
    columns: table => new
    {
        Id = table.Column<Guid>(type: "uniqueidentifier", nullable: false),
        Deleted = table.Column<bool>(type: "bit", nullable: false),
        Data = table.Column<string>(type: "nvarchar(max)", nullable: false)
    },
    constraints: table =>
    {
        table.PrimaryKey("PK_OwnerEntities", x => x.Id);
    });

Note that the Data column is string type.

A more detailed example can be found here .