Polecat as Document DB

Polecat allows you to use SQL Server 2025 as a document database. Documents are stored as JSON using the native json data type, with each document type getting its own table (prefixed with pc_doc_).

Key Concepts

• Documents are plain .NET objects serialized to JSON
• Sessions provide a unit of work pattern for batching changes
• LINQ queries translate to SQL Server JSON path expressions
• Automatic schema management creates and updates tables as needed

Document Tables

Each document type gets its own table:

Column	Type	Description
id	Varies	Primary key (Guid, string, int, long)
data	json	Serialized document body
type	nvarchar(250)	.NET type discriminator
last_modified	datetimeoffset	Last modification timestamp
created	datetimeoffset	Creation timestamp
dotnet_type	nvarchar(500)	Full .NET type name
tenant_id	nvarchar(250)	Tenant identifier (conjoined tenancy)

Additional columns are added for features like soft deletes, versioning, and metadata.

Quick Example

// Define a document
public class User
{
    public Guid Id { get; set; }
    public string FirstName { get; set; } = "";
    public string LastName { get; set; } = "";
    public string Email { get; set; } = "";
}

// Store a document
await using var session = store.LightweightSession();
var user = new User { FirstName = "Jane", LastName = "Doe", Email = "jane@example.com" };
session.Store(user);
await session.SaveChangesAsync();

// Load by ID
var loaded = await session.LoadAsync<User>(user.Id);

// Query with LINQ
var users = await session.Query<User>()
    .Where(x => x.LastName == "Doe")
    .ToListAsync();