Swevo.EFCore.JsonColumn

[](https://www.nuget.org/packages/Swevo.EFCore.JsonColumn)

Compile-time JSON column configuration for EF Core 8+. Stamp [JsonColumn] on owned navigation properties and the source generator emits ConfigureJsonColumns(ModelBuilder) so you do not have to hand-write repetitive OwnsOne(..., b => b.ToJson()) boilerplate.

Quick-start

dotnet add package Swevo.EFCore.JsonColumn

1 — Mark JSON-owned navigations

using EFCore.JsonColumn;

public class Address
{
    public string Street { get; set; } = "";
    public string City { get; set; } = "";
}

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

    [JsonColumn]
    public Address ShippingAddress { get; set; } = new();
}

2 — Configure your DbContext

public class AppDbContext(DbContextOptions<AppDbContext> options) : DbContext(options)
{
    protected override void OnModelCreating(ModelBuilder modelBuilder)
        => modelBuilder.ConfigureJsonColumns();
}

3 — Generated output

modelBuilder.Entity<global::MyApp.Order>(entity =>
{
    entity.OwnsOne(e => e.ShippingAddress, b => b.ToJson());
});

How it works

• [JsonColumn] marks an owned reference navigation for JSON-column configuration
• The incremental source generator scans the full compilation for annotated properties
• One generated ConfigureJsonColumns(ModelBuilder) method groups properties by owning entity
• Each property becomes entity.OwnsOne(e => e.PropertyName, b => b.ToJson())

Requirements

• .NET 8+
• EF Core 8+
• JSON-column properties must be reference types

Applying [JsonColumn] to a value type produces warning JSCOL001.

Also by the same author

🌐 Full suite overview: swevo.github.io

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License

MIT