The official Entity Framework Core provider for ClickHouse, built on top of ClickHouse.Driver.

await using var ctx = new AnalyticsContext();

var topPages = await ctx.PageViews
    .Where(v => v.Date >= new DateOnly(2024, 1, 1))
    .GroupBy(v => v.Path)
    .Select(g => new { Path = g.Key, Views = g.Count() })
    .OrderByDescending(x => x.Views)
    .Take(10)
    .ToListAsync();

public class AnalyticsContext : DbContext
{
    public DbSet<PageView> PageViews { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        => optionsBuilder.UseClickHouse("Host=localhost;Port=9000;Database=analytics");
}

public class PageView
{
    public long Id { get; set; }
    public string Path { get; set; }
    public DateOnly Date { get; set; }
    public string UserAgent { get; set; }
}

This provider is in early development. It supports read-only queries and inserts — you can map entities to existing ClickHouse tables, query them with LINQ, and write data via SaveChanges.

Where, OrderBy, Take, Skip, Select, First, Single, Any, Count, Distinct, AsNoTracking

GroupBy with Count, LongCount, Sum, Average, Min, Max — including HAVING (.Where() after .GroupBy()), multiple aggregates in a single projection, and OrderBy on aggregate results.

Contains, StartsWith, EndsWith, IndexOf, Replace, Substring, Trim/TrimStart/TrimEnd, ToLower, ToUpper, Length, IsNullOrEmpty, Concat (and + operator)

Math.Abs, Floor, Ceiling, Round, Truncate, Pow, Sqrt, Cbrt, Exp, Log, Log2, Log10, Sign, Sin, Cos, Tan, Asin, Acos, Atan, Atan2, RadiansToDegrees, DegreesToRadians, IsNaN, IsInfinity, IsFinite, IsPositiveInfinity, IsNegativeInfinity — with both Math and MathF overloads.

SaveChanges supports INSERT operations using the driver's native InsertBinaryAsync API — RowBinary encoding with GZip compression, far more efficient than parameterized SQL.

await using var ctx = new AnalyticsContext();

ctx.PageViews.Add(new PageView
{
    Id = 1,
    Path = "/home",
    Date = new DateOnly(2024, 6, 15),
    UserAgent = "Mozilla/5.0"
});

await ctx.SaveChangesAsync();

Entities transition from Added to Unchanged after save, just like any other EF Core provider.

Batch size is configurable (default 1000) — controls how many entities are accumulated before flushing to ClickHouse:

optionsBuilder.UseClickHouse("Host=localhost", o => o.MaxBatchSize(5000));

For high-throughput loads that don't need change tracking, use BulkInsertAsync:

var events = Enumerable.Range(0, 100_000)
    .Select(i => new PageView { Id = i, Path = $"/page/{i}", Date = DateOnly.FromDateTime(DateTime.Today) });

long rowsInserted = await ctx.BulkInsertAsync(events);

This calls InsertBinaryAsync directly, bypassing EF Core's change tracker entirely. Entities are not tracked after insert.

• UPDATE / DELETE (ClickHouse mutations are async, not OLTP-compatible)
• Migrations
• JOINs, subqueries, set operations
• Nested type, Variant, Dynamic, JSON, Geo types

dotnet build
dotnet test    # requires Docker (uses Testcontainers)

Targets .NET 10.0, EF Core 10.