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Data Layer Guide

Muonroi provides MDbContext, MRepository<T>, and MQuery<T> as the standard EF Core building blocks.

DbSet and queryable access​

DbSet<T> is the raw EF Core entry point. Higher-level application code should usually query through MRepository<T> or MQuery<T>.

Those abstractions typically expose a filtered queryable that excludes soft-deleted rows such as IsDeleted = false. You can continue composing LINQ on top of that default query.

SaveChangesAsync and SaveEntitiesAsync​

MDbContext extends save behavior to update timestamps and other framework metadata before persisting.

SaveEntitiesAsync is the broader unit-of-work path used when you need both persistence and domain-event dispatching:

  1. Update framework-managed metadata.
  2. Save entity changes.
  3. Dispatch domain events.
  4. Commit the surrounding transaction when applicable.

Use SaveChangesAsync for straightforward persistence. Use SaveEntitiesAsync when a workflow must publish domain events as part of the same business operation.

Domain events​

MEntity stores pending domain events. After persistence, MDbContext dispatches those events through MediatR.

Typical event shapes include:

  • MEntityCreatedEvent
  • MEntityChangedEvent
  • MEntityDeletedEvent
  • Batch variants such as MEntitiesCreatedEvent

Batch operations may attach the batch event to one tracked entity so the unit of work can dispatch a single logical event for the full operation.

Unit of work​

MDbContext implements IMUnitOfWork and exposes transaction helpers such as:

  • BeginTransactionAsync
  • CommitTransactionAsync
  • RollbackTransaction

MRepository<T> surfaces the current unit of work through UnitOfWork, which lets multiple repositories participate in the same transaction boundary.

Register the data layer​

Use the provided registration helper from Program.cs:

services.AddDbContextConfigure<MyDbContext, MyPermission>(configuration);

That setup can resolve different storage providers based on configuration. Keep production connection strings in secret storage rather than inline appsettings.

Paging with MQuery​

MQuery<T> commonly exposes GetPagedAsync so a query can return items plus paging metadata in one call.

IQueryable<MUser> query = _context.Set<MUser>().Where(x => !x.IsDeleted);

MPagedResult<UserDto> result = await GetPagedAsync(
    query,
    pageIndex: 1,
    pageSize: 10,
    selector: x => new UserDto
    {
        Id = x.EntityId,
        Name = x.Username
    });

The result usually contains row count, current page, page size, and projected items.