Defining Models¶

All models in Meerkat must inherit from the abstract base class Schema<TId>, where TId is the type of the document's unique identifier. The Id property is mapped to the MongoDB _id field.

Basic Model Definition¶

using meerkat;
using MongoDB.Bson;

public class Student : Schema<ObjectId>
{
    public string FirstName { get; set; } = string.Empty;
    public string LastName { get; set; } = string.Empty;

    public Student()
    {
        Id = ObjectId.GenerateNewId();
    }
}

Identifier Types¶

The generic type parameter TId requires IEquatable<TId>. Common ID types supported in Meerkat include:

MongoDB.Bson.ObjectId
System.Guid
string
int / long
Any custom value type implementing IEquatable<TId>

Collection Configuration¶

Apply the [Collection] attribute to customise collection names, timestamp tracking, and soft deletion:

using meerkat;
using meerkat.Attributes;
using MongoDB.Bson;

[Collection(Name = "people", TrackTimestamps = true, SoftDelete = true)]
public class Student : Schema<ObjectId>
{
    public string FirstName { get; set; } = string.Empty;
    public string LastName { get; set; } = string.Empty;
}

Attribute Options¶

Property	Type	Default	Description
`Name`	`string`	`null`	Overrides the default collection name. If not specified, Meerkat generates a pluralised, lowercased name from the class name (e.g. `Student` → `students`).
`TrackTimestamps`	`bool`	`false`	When `true`, automatically sets `CreatedAt` on first save and updates `UpdatedAt` on every save or partial update.
`SoftDelete`	`bool`	`false`	When `true`, enables soft delete. `Remove*` sets `DeletedAt` instead of physically deleting documents, and queries automatically exclude soft-deleted records.

Timestamps¶

When TrackTimestamps = true is set on the [Collection] attribute:

CreatedAt (DateTime?): Populated with UTC timestamp when the document is first saved via Save or SaveAll.
UpdatedAt (DateTime?): Updated to the current UTC timestamp on every Save, SaveAll, and fluent partial Update execution.

[Collection(TrackTimestamps = true)]
public class Article : Schema<Guid>
{
    public string Title { get; set; } = string.Empty;
    public string Content { get; set; } = string.Empty;
}

Soft Delete Overview¶

When SoftDelete = true is set:

DeletedAt (DateTimeOffset?): Persisted as a UTC BSON date when the document is soft-deleted.
IsDeleted (bool): A computed property returning DeletedAt != null (ignored during serialisation).
An index on DeletedAt (deleted_at_idx) is created automatically.

For querying, restoring, and permanently deleting soft-deleted entities, see Persistence & Transactions.