EFCore5LogChanges.cs

// ef core 5
// after add/modify/delete some entities at a sync api, i recommend logging changes deeply.
// also it is best practice that returning the `changes` to client throw responce both in seccess and fail situation.
private object logContextChanges()
{
    var changes = _context.ChangeTracker.Entries()
        .Where(i => i.State != EntityState.Unchanged).Select(t => new
        {
            state = t.State.ToString(),
            type = t.Entity.GetType().FullName,
            props =
              t.State == EntityState.Added ?
              t.Properties.Select(p => new
              {
                  propName = p.Metadata.Name,
                  propType = p.Metadata.ClrType.FullName,
                  oldValue = (object)null,
                  newValue = p.CurrentValue,
                  modified = (bool?)null,
                  changed = (bool?)null,
              }) :
              t.State == EntityState.Modified ?
              t.Properties.Select(p => new
              {
                  propName = p.Metadata.Name,
                  propType = p.Metadata.ClrType.FullName,
                  oldValue = p.OriginalValue,
                  newValue = p.CurrentValue,
                  modified = (bool?)p.IsModified,
                  changed = (bool?)!(p.CurrentValue == p.OriginalValue || p.CurrentValue.Equals(p.OriginalValue)),
              }) :
              t.Properties.Select(p => new
              {
                  propName = p.Metadata.Name,
                  propType = p.Metadata.ClrType.FullName,
                  oldValue = p.CurrentValue,
                  newValue = (object)null,
                  modified = (bool?)null,
                  changed = (bool?)null,
              }),
        }).ToArray();
    return new
    {
        changesCount = changes.GroupBy(i => new { i.type, i.state }).Select(i => new
        {
            i.Key.state,
            i.Key.type,
            count = i.Count(),
            changedCount = i.Where(j => j.props.Any(k => k.changed != false)).Count(),
        }).ToArray(),
        changes = changes
    };
    var changesText = System.Text.Json.JsonSerializer.Serialize(changes, new System.Text.Json.JsonSerializerOptions(System.Text.Json.JsonSerializerDefaults.Web) { WriteIndented = true });
    _logger.LogInformation($"Sync site info... changes = {changesText}");
}