EFCore.Snowflake 8.0.8

About

EntityFrameworkCore.Snowflake is the Entity Framework Core (EF Core) provider for Snowflake.

It is build on top of Snowflake.Data.

How to Use

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        // Replace with your connection string.
        var connectionString = "account=YOUR_ACCOUNT;host=UR_HOST.us-east-1.snowflakecomputing.com;user=UR_USER;password=UR_PASSWORD;db=TESTDB;schema=PUBLIC;warehouse=UR_WAREHOUSE";

        // Replace 'YourDbContext' with the name of your own DbContext derived class.
        services.AddDbContext<YourDbContext>(
            dbContextOptions => dbContextOptions
                .UseSnowflake(connectionString)
        );
    }
}

Scaffolding

If you wish to create model from existing Snowflake database, then follow this steps. Provider name is EFCore.Snowflake. Ensure you have ef tools installed (dotnet tool install --global dotnet-ef).

Database generation

Please be aware, that Snowflake default naming convention is UPPERCASE, while C# default naming convention is PascalCase. In order to follow Snowflake's uppercase convention when generating new database with code-first approach you have to map each table and column to database name with uppercase. Use .ToTable("TABLE_NAME") and entity.Property(e => e.Id).HasColumnName("ID") mapping methods.

Type mapping

• All basic C# types are supported.
• Spatial types are not supported
• When scaffolding Variant, Array or Object column type - it is mapped as C# string type with json data
• Snowflake Array column can be mapped to C# arrays. Example:

public class SampleModel
{
    public long Id { get; set; }
    public string[]? ArrayColumn { get; set; }
}

public class SnowflakeDbContext : DbContext
{
    public DbSet<SampleModel> Models { get; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        => optionsBuilder.UseSnowflake();

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.HasDefaultSchema("PUBLIC");

        modelBuilder.Entity<SampleModel>(entity =>
        {
            entity.ToTable("SAMPLE_MODEL_", "PUBLIC");

            entity.HasKey(e => e.Id);

            entity.Property(e => e.Id)
                .HasColumnType("NUMBER(38,0)")
                .HasColumnName("ID");

            entity.Property(e => e.ArrayColumn)
                .HasColumnType("ARRAY")
                .HasColumnName("ARRAY_COLUMN");;
        });
    }
}

Feedback

Feel free to submit any feedback - bug reports or feature requests. All feedback is welcome at GitHub repository.

Key Features

• Query support
• Auto increment
• Scaffolding support
• Database versioning support
• Sequences support, along with primary key
• Transient tables scaffolding and generation - use entity.ToTable("TABLE_NAME", t => t.IsTransient())

Known issues

• Spatial types not supported
• Variant type inserts data with json escaping (bug in Snowflake.Data connector)
• Database name is required to be named UPPERCASE (bug in Snowflake.Data)
• More advanced queries, such as LEFT LATERAL JOIN or more complex subqueries fails, because they are not supported by Snowflake right now

Related Packages

• Other Packages
  • Snowflake ADO.NET connetor Snowflake.Data.
  • Microsoft.EntityFrameworkCore

License

EntityFrameworkCore.Snowflake is released as open source under the GNU Lesser General Public License v3.0 only.