Lyo.ChangeTracker.Postgres 1.0.1

Lyo.ChangeTracker.Postgres

PostgreSQL implementation of Lyo.ChangeTracker. Persists entity-scoped change history using Lyo.EntityReference.Models.EntityRef for both the target entity and the optional actor.

Features

• PostgresChangeTracker implementing both IChangeTracker and Lyo.Health.IHealth
• EF Core migrations in the change_tracker schema (PostgresChangeTrackerOptions.Schema)
• Queryable history by entity, entity type, or change id (newest first)
• DeleteForEntityAsync to drop all history for a target entity
• Optional automatic migrations on startup via EnableAutoMigrations

Examples

Quick Start

services.AddPostgresChangeTracker(new PostgresChangeTrackerOptions {
    ConnectionString = configuration.GetConnectionString("ChangeTracker")!,
    EnableAutoMigrations = true
});

services.AddPostgresChangeTrackerFromConfiguration(configuration);

Migrations

export CHANGE_TRACKER_CONNECTION_STRING="Host=localhost;Database=change_tracker;Username=postgres;Password=postgres"
dotnet ef migrations add MigrationName --project Core/ChangeTracker/Lyo.ChangeTracker.Postgres

Registration

The package layers registration helpers so hosts can pick the level of integration they need:

Health

PostgresChangeTracker implements Lyo.Health.IHealth with HealthCheckName = "change-tracker-postgres". The probe opens a ChangeTrackerDbContext and runs Database.CanConnectAsync, returning a HealthResult with the schema name in its data bag — so the tracker contributes to host health endpoints that resolve IEnumerable<IHealth>.

Schema

• All tables live in the change_tracker schema (see PostgresChangeTrackerOptions.Schema).
• change_tracker.changes — subject (for_entity_* / SubjectEntityType), optional actor (from_entity_* / ActorEntityType), nullable tenant_id (uuid), JSON OldValues, JSON ChangedProperties, optional ChangeType / Message, and Timestamp.

Tenancy

ChangeRecord carries an optional TenantId; null denotes a system / untenanted row. PostgresChangeTracker runs every record through TenancyResolver.Resolve using the policy configured in PostgresChangeTrackerOptions.Tenancy (inheriting from EntityRefOptions.Mode when unset) before persisting:

• SystemOnly — caller TenantId is ignored; the row stores null.
• SingleTenantDefault (default) — caller value, falling back to Tenancy.DefaultTenantId then EntityRefOptions.DefaultTenantId.
• MultiTenantStrict — caller must supply a non-empty TenantId or persistence throws.

The ix_changes_tenant index supports per-tenant lookups. Use the WhereTenant / WhereTenantOrSystem helpers from Lyo.EntityReference.Postgres to query the table.

{
  "PostgresChangeTracker": {
    "ConnectionString": "Host=localhost;Database=change_tracker;...",
    "Tenancy": { "Mode": "SystemOnly" }
  }
}

Dependencies

Generated from ProjectReference / PackageReference (same model as docs/Lyo.ProjectGraph.html).

• Lyo.ChangeTracker — (direct, lyo)
• Lyo.EntityReference.Models — (direct, lyo)
• Lyo.EntityReference.Postgres — (direct, lyo)
• Lyo.Exceptions — (direct, lyo)
• Lyo.Health — (direct, lyo)
• Lyo.Postgres — (direct, lyo)
• Microsoft.Extensions.Configuration.Binder 10.0.5 — (direct, microsoft)
• Lyo.Common — (transitive, lyo)
• Microsoft.EntityFrameworkCore 10.0.5 — (transitive, microsoft)
• Microsoft.EntityFrameworkCore.Design 10.0.5 — (transitive, microsoft)
• Microsoft.EntityFrameworkCore.Relational 10.0.5 — (transitive, microsoft)
• Microsoft.Extensions.DependencyInjection.Abstractions 10.0.5 — (transitive, microsoft)
• Microsoft.Extensions.Hosting.Abstractions 10.0.5 — (transitive, microsoft)
• Microsoft.Extensions.Logging.Abstractions 10.0.5 — (transitive, microsoft)
• Microsoft.Extensions.Options 10.0.5 — (transitive, microsoft)
• Microsoft.Extensions.Options.ConfigurationExtensions 10.0.5 — (transitive, microsoft)
• Npgsql.EntityFrameworkCore.PostgreSQL 10.0.3 — (transitive, third-party)
• System.Memory 4.6.3 — (transitive, microsoft, netstandard2.0)
• System.Text.Json 10.0.5 — (transitive, microsoft, netstandard2.0)