JackcessDotNet 1.0.0

JackcessDotNet

Pure .NET 8 library for reading and writing Microsoft Access (.mdb / .accdb) files. No ODBC, no ACE drivers, no native dependencies — runs anywhere .NET 8 runs (Windows, Linux, macOS, containers).

This is a C# port of the spannm/jackcess Java project (a maintained fork of the original Jackcess by James Ahlborn). The upstream Java project remains the source of truth for the Jet file format; this port tracks its behaviour and reuses its test corpus for verification.

Install

dotnet add package JackcessDotNet

Quick start

using JackcessDotNet;

// Open an existing .mdb / .accdb (auto-detects version)
using var db = Database.Open("Northwind.mdb");

foreach (var name in db.ListTables())
    Console.WriteLine(name);

var customers = db.GetTable("Customers");
foreach (var row in customers.NewCursor())
    Console.WriteLine($"{row["CustomerID"]}  {row["CompanyName"]}");

// Create a new database, define a schema, insert rows
using var fresh = Database.Create("MyData.mdb", JetVersion.Jet4);
var people = fresh.CreateTable("People", new[]
{
    new ColumnBuilder("Id",   DataType.Long).Build(),
    new ColumnBuilder("Name", DataType.Text).MaxLength(50).Build(),
}, primaryKey: "Id");
people.Insert(new Row { ["Id"] = 1, ["Name"] = "Alice" });

Importing from DataTable, DataSet, or IEnumerable<T>

Skip the schema boilerplate — the importer infers columns from the source type:

using var db = DatabaseImporter.CreateFromDataTable("out.mdb", myDataTable);

// or add into an existing database
db.ImportTable(otherDataTable, tableName: "Extra", primaryKey: "Id");
db.ImportTables(myDataSet);

db.ImportTable<Customer>(customers, primaryKey: "Id");

POCO mapping respects [Key], [Column("X")], [MaxLength], [NotMapped], and [DatabaseGenerated(Identity)]. Long strings (>255 chars) auto-promote to Memo; large byte arrays (>255 bytes) to OLE. Unmappable types can fall back to Memo via ImportOptions.FallbackUnmappableToString = true.

Exporting back

DataTable          dt    = db.ExportToDataTable("Customers");
DataSet            ds    = db.ExportToDataSet();
IEnumerable<Customer> cs = db.ExportToCollection<Customer>("Customers");

The IEnumerable<T> path is lazy via yield, so Take(n) stops early without materialising the whole table.

Status

Type round-trip cheat sheet

Credits

This project would not exist without the years of reverse-engineering work done by James Ahlborn (original Jackcess) and Markus Spann (maintained fork at spannm/jackcess). The Jet binary format is documented effectively only through their Java source.

License

Apache License 2.0 — same as the upstream Jackcess project.