EntityFrameworkCore.Jet.Odbc 11.0.0-alpha.2

EntityFrameworkCore.Jet

EntityFrameworkCore.Jet is an Entity Framework Core provider for Microsoft Jet/ACE databases (supporting the Microsoft Access database file formats MDB and ACCDB).

Compatibility Matrix

The major version corresponds to the major version of EF Core (i.e. EFCore.Jet 3.x is compatible with EF Core 3.y). It runs on Windows operating systems only and can be used with either ODBC or OLE DB together with their respective Access Database driver/provider.

Requirements

EntityFrameworkCore.Jet requires:

• Windows.
• A Microsoft Access Database Engine driver/provider for either ODBC or OLE DB.
• A process architecture (x86 or x64) that matches the installed Access driver/provider.

The provider works with Microsoft Access MDB and ACCDB database files.

LibRed - native managed engine (in development)

LibRed is a from-scratch, fully managed implementation of the Jet/ACE engine that also lives in this repository. It reads and writes MDB/ACCDB files directly - no ODBC, OLE DB, DAO or ADOX - so none of the requirements above apply to it: no Windows, no installed Access driver, and no need to match your process architecture to one. It runs on Linux, macOS and ARM64, which CI proves by running its suites on all five platforms with no Access engine installed anywhere.

It reads and writes real database files, creates them from nothing (no DAO, no template file), runs SQL end to end, and an EF Core DbContext round-trips through it. The on-disk format it depends on is documented and verified in src/LibRed/docs/format/.

optionsBuilder.UseLibRed(@"C:\Data\Blogging.accdb");

Because LibRed owns both the SQL generator and the engine that parses the result, it does not have to please ACE. UseLibRed takes an optional LibRedSqlMode:

• LibRedSqlMode.Extended (the default) - LibRed's own SQL generator, free of the Jet dialect's limitations. It emits standard SQL that ACE has no syntax for at all: CROSS/OUTER APPLY, window functions, OFFSET/FETCH paging, FULL OUTER JOIN, CASE, COALESCE, NULLIF, set operations inside subquery predicates, and flat unparenthesised join chains.
• LibRedSqlMode.Compatible - the same SQL generator the EntityFrameworkCore.Jet provider uses, so the statements LibRed receives are ones ACE would also accept. Use it when the same queries have to run against both engines.

Each mode has its own EF Core specification suite, since the two produce different SQL for the same query.

Packages

The Jet provider (Windows, ACE driver required):

• EntityFrameworkCore.Jet - the EF Core provider.
• EntityFrameworkCore.Jet.Data - the shared ADO.NET-style data access layer used by the provider packages.
• EntityFrameworkCore.Jet.Odbc - ODBC support, including the UseJetOdbc extension method.
• EntityFrameworkCore.Jet.OleDb - OLE DB support, including the UseJetOleDb extension method.

Shared by both providers:

• EntityFrameworkCore.Jet.Common - the Jet-dialect EF Core services (query pipeline and translators, migrations SQL generation, conventions, annotations, value generation). Cross-platform, and it does not reference the ACE-bound data layer, which is what lets LibRed sit on it.

LibRed, the native managed engine (cross-platform, no driver):

• LibRed.Core - the MDB/ACCDB file format reader/writer.
• LibRed.Sql - the SQL front end (ANTLR grammar, AST, binder).
• LibRed.Engine - the query planner and executor.
• LibRed.Ado - the ADO.NET surface.
• EntityFrameworkCore.LibRed - the EF Core provider, including UseLibRed.

Getting Started

Install the provider package for the data access technology you want to use:

dotnet add package EntityFrameworkCore.Jet.OleDb

or:

dotnet add package EntityFrameworkCore.Jet.Odbc

Configure your DbContext with the matching UseJet... extension method:

using Microsoft.EntityFrameworkCore;

public class BloggingContext : DbContext
{
    public DbSet<Blog> Blogs => Set<Blog>();

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        => optionsBuilder.UseJetOleDb(
            @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Data\Blogging.accdb");
}

public class Blog
{
    public int Id { get; set; }
    public string? Url { get; set; }
}

For ODBC, use UseJetOdbc instead:

optionsBuilder.UseJetOdbc(
    @"Driver={Microsoft Access Driver (*.mdb, *.accdb)};Dbq=C:\Data\Blogging.accdb;");

NuGet Feeds

Official Releases

All official releases are available on nuget.org.

CI Builds

CI publishes each build to MyGet. To use the latest CI builds, add a NuGet.config file to your solution root, add the feeds you are interested in and enable prereleases:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <packageSources>
    <add key="efcorejet-daily" value="https://www.myget.org/F/cirrusred/api/v3/index.json" />
    <add key="efcorejet-daily-debug" value="https://www.myget.org/F/cirrusred-debug/api/v3/index.json" />
    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
  </packageSources>
</configuration>

There are two CI build feeds available, one with (optimized) Release configuration builds and one with (unoptimized) Debug configuration builds. All packages use SourceLink.

Fluent API

In order to simplify writing code for more than just one provider, some Fluent API method names have been made specific to Jet. Examples are:

• UseIdentityColumn → UseJetIdentityColumn
• UseIdentityColumns → UseJetIdentityColumns

Further information

More information can be found on our Wiki.

Questions

Questions, bug reports, and feature requests can be opened as GitHub issues.