NuExt.System.Data 0.8.5

NuExt.System.Data

NuExt.System.Data is a lightweight, provider-independent data access foundation for .NET applications and application frameworks, combining practical ADO.NET extensions, explicit database context ownership, reusable DAL abstractions, and deterministic database migration orchestration.

Why NuExt.System.Data?

• Provider-independent � common DAL and migration contracts remain separate from provider-specific connections, transactions, and history storage
• Ownership-aware � DAL operations explicitly distinguish owned contexts from caller-provided contexts
• Composable � independent operations and larger transactional units of work use the same DAL implementation
• Migration-safe � configured migrations and applied history are validated as one ordered sequence before pending changes run
• ADO.NET-focused � typed reader, row, and table helpers without an ORM or tracking model
• Consistent across runtimes � a stable API surface across modern .NET, .NET Standard, and .NET Framework
• Dependency-light � no required ORM, hosting model, dependency injection container, or database provider

Designed for

NuExt.System.Data is intended for application and framework authors who need:

• a small reusable foundation above ADO.NET rather than a full ORM;
• explicit ownership and transaction boundaries in data access code;
• the same DAL methods for standalone operations and caller-controlled units of work;
• deterministic migration orchestration with provider-specific execution;
• strict validation of migration ordering and applied history;
• compatibility across modern .NET and legacy .NET Framework targets.

Core infrastructure

ADO.NET extensions

• DataReaderExtensions adds name-based typed accessors and nullable getters for older targets.
• DataRowExtensions provides typed and nullable conversions by index, name, DataColumn, or DataRowVersion.
• DataTableExtensions provides focused table operations without object tracking.
• Compatibility implementations resolve column names to ordinals and preserve provider behavior.

DAL and database contexts

• IDbContext defines the lifetime contract for provider-specific database contexts.
• IDbContextExecutor<TDbContext> creates and executes owned context scopes while also supporting operations over existing contexts.
• DalBase<TDbContext> centralizes DAL execution and exposes the same synchronous and asynchronous operation model for owned and borrowed contexts.
• DbContextExtensions adds focused helpers around context execution without hiding ownership boundaries.

Explicit context ownership

The DAL infrastructure supports two execution models:

• Owned context � when no context is supplied, the provider-specific executor creates and owns the context, including connection lifetime, transaction completion, and cleanup.
• Borrowed context � when an existing context is supplied, the DAL participates in the caller's unit of work without committing, rolling back, or disposing that context.

This design allows a DAL operation to run independently or compose with other operations inside one caller-controlled transaction without duplicating data access logic.

Deterministic database migrations

Migration orchestration is provider-independent; transaction handling and history persistence are provider-specific.

• DbMigration<TContext> represents an ordered schema or data change with a stable identifier.
• DbMigrationContext carries cancellation and provides a base for provider-specific state.
• DbMigrator<TContext> validates migration configuration and history before applying pending migrations.
• IDbMigrationExecutor<TContext> defines the provider-specific execution and transaction boundary.
• IDbMigrationHistory<TContext> defines migration history storage.
• AppliedDbMigration records the sequence, identifier, UTC application time, and optional version.

Before executing pending migrations, the migrator verifies that:

• configured migration identifiers are non-empty and unique;
• applied history does not contain more entries than the current configuration;
• applied sequence numbers are contiguous and one-based;
• every applied identifier matches the configured migration at the same position.

This treats migration history as a strict prefix of the configured migration sequence and prevents silently continuing from reordered, removed, duplicated, or otherwise inconsistent migrations.

Cancellation and transaction boundaries

• Cancellation is checked before execution and before each pending migration.
• The migration context passes the cancellation token to provider code and migrations.
• A migration is recorded only after its Up operation completes successfully.
• IDbMigrationExecutor<TContext> controls transactions and keeps migration history consistent.

Compatibility

• .NET Standard 2.0+, .NET 8/9/10, and .NET Framework 4.6.2+
• Works with provider-specific implementations built on ADO.NET
• Includes selected ADO.NET API backports for older targets
• Does not require Entity Framework or another ORM

Installation

Via NuGet:

dotnet add package NuExt.System.Data

Or via Visual Studio:

1. Go to Tools -> NuGet Package Manager -> Manage NuGet Packages for Solution....
2. Search for NuExt.System.Data.
3. Click "Install".

Provider implementation

For a complete provider implementation, transaction strategy, migration history store, and usage example, see:

• NuExt.System.Data.SQLite

Ecosystem

• NuExt.System
• NuExt.System.Data.SQLite
• NuExt.Minimal.Mvvm
• NuExt.Minimal.Mvvm.SourceGenerator
• NuExt.Minimal.Behaviors.Wpf
• NuExt.Minimal.Mvvm.Wpf
• NuExt.Minimal.Mvvm.MahApps.Metro

Contributing

Issues and PRs are welcome. Keep changes minimal and performance-conscious.

License

MIT. See LICENSE.