NSchema.Postgres 2.0.0

NSchema.Postgres

PostgreSQL provider for NSchema, the declarative database schema migration library for .NET.

This package plugs PostgreSQL-specific implementations of NSchema's ISchemaProvider (live-database introspection) and ISqlPlanner (DDL generation) into your application, and contributes Postgres-only SqlType helpers.

Getting started

Install the core package and this provider:

dotnet add package NSchema
dotnet add package NSchema.Postgres

Register Postgres against an NSchemaApplicationBuilder:

using NSchema;
using NSchema.Postgres;

var builder = NSchemaApplication.CreateBuilder(args);

builder
    .AddSchemasFromAssemblyContaining<Program>()
    .UseCurrentSchemaPostgres(connectionString);

var app = builder.Build();
await app.Apply();

On startup NSchema introspects the database through this provider, diffs it against your declared schema, and applies the resulting plan.

Configuration

UseCurrentSchemaPostgres has four overloads. The three connection-aware overloads register an NpgsqlDataSource for you (via AddNpgsqlDataSource) and wire up the current schema provider and SQL planner; the no-arg overload assumes you've already registered an NpgsqlDataSource yourself.

// 1. Connection string.
builder.UseCurrentSchemaPostgres("Host=localhost;Database=app;Username=postgres;Password=postgres");

// 2. Configure the data source builder directly.
builder.UseCurrentSchemaPostgres(b => b
    .EnableDynamicJson()
    .UseLoggerFactory(loggerFactory)
);

// 3. As above, with access to the IServiceProvider.
builder.UseCurrentSchemaPostgres((sp, b) => b.UseLoggerFactory(sp.GetRequiredService<ILoggerFactory>()));

// 4. Bring your own data source.
builder.Services.AddNpgsqlDataSource(connectionString);
builder.UseCurrentSchemaPostgres();

Postgres-specific types

SqlTypePostgresExtensions adds Postgres-only members to SqlType:

users.Column("email", SqlType.Citext).NotNull();
users.Column("metadata", SqlType.Jsonb);

citext requires CREATE EXTENSION citext; in the target database — NSchema.Postgres does not create extensions for you.

Supported schema objects

The introspector reads, and the planner emits DDL for:

• Schemas (including comments and GRANTs on the schema itself)
• Tables (including comments and table-level GRANTs)
• Columns (types, nullability, defaults, comments)
• Primary keys
• Foreign keys
• Indexes, including unique indexes and index comments

Requirements

• .NET 10
• PostgreSQL (tested against postgres:17-alpine via Testcontainers)

License

See LICENSE.