CSharpDB.Engine 1.2.0

CSharpDB.Engine

Lightweight embedded SQL database engine for .NET with single-file storage, WAL durability, concurrent readers, and a typed Collection<T> NoSQL API.

Overview

CSharpDB.Engine is the main entry point for embedding CSharpDB in your .NET application. It combines the SQL parser, query planner, and B+tree storage engine into a single Database class with two access paths: a full SQL engine and a zero-SQL Collection<T> document API. No external dependencies, no server process, just a single .db file on disk.

Features

• SQL engine: DDL, DML, JOINs, aggregates, GROUP BY, HAVING, CTEs, views, triggers, indexes
• NoSQL Collection API: Typed Collection<T> with Put/Get/Delete/Scan/Find
• Single-file storage: All data in one .db file with 4 KB B+tree pages
• WAL durability: Write-ahead log with crash recovery
• Concurrent readers: Snapshot-isolated readers alongside a single writer
• Statement cache: LRU cache (512 capacity) for parsed and planned queries
• Fast-path lookups: Direct B+tree access for SELECT ... WHERE pk = value
• Async-first: All APIs are async/await from top to bottom

Usage

SQL API

using CSharpDB.Engine;

// Open or create a database
await using var db = await Database.OpenAsync("myapp.db");

// Create a table
await db.ExecuteAsync("""
    CREATE TABLE users (
        id INTEGER PRIMARY KEY,
        name TEXT,
        email TEXT
    )
    """);

// Insert data
await db.ExecuteAsync("INSERT INTO users VALUES (1, 'Alice', 'alice@example.com')");

// Query data
var result = await db.ExecuteAsync("SELECT name, email FROM users WHERE id = 1");
while (await result.MoveNextAsync())
{
    Console.WriteLine($"{result.Current[0].AsText} - {result.Current[1].AsText}");
}

// Transactions
await db.BeginTransactionAsync();
await db.ExecuteAsync("INSERT INTO users VALUES (2, 'Bob', 'bob@example.com')");
await db.CommitAsync();

NoSQL Collection API

// Get a typed collection
var users = await db.GetCollectionAsync<User>("users");

// Put a document
await users.PutAsync("alice", new User { Name = "Alice", Age = 30 });

// Get a document
var alice = await users.GetAsync("alice");

// Scan all documents
await foreach (var user in users.ScanAsync())
{
    Console.WriteLine(user.Name);
}

// Find with predicate
var adults = await users.FindAsync(u => u.Age >= 18);

Concurrent Readers

// Create a snapshot-isolated reader session
using var reader = db.CreateReaderSession();
var result = await reader.ExecuteAsync("SELECT * FROM users");
// Reads from a consistent snapshot while the writer continues

Installation

dotnet add package CSharpDB.Engine

Dependencies

• CSharpDB.Core - shared type system
• CSharpDB.Sql - SQL parser
• CSharpDB.Storage - B+tree storage engine
• CSharpDB.Execution - query planner and operators

Related Packages

License

MIT - see LICENSE for details.