Custom query in EditRecord

 Section::make()
                    ->schema([
                        Placeholder::make('courses_count')
                            ->label(__('Total Courses'))
                            ->content(fn (CourseCategory $record): ?string => $record->courses_count),
                        Placeholder::make('created_at')
                            ->label('Created at')
                            ->content(fn (CourseCategory $record): ?string => $record->created_at?->diffForHumans()),

                        Placeholder::make('updated_at')
                            ->label('Last modified at')
                            ->content(fn (CourseCategory $record): ?string => $record->updated_at?->diffForHumans()),
                    ])
                    ->columnSpan(['lg' => 1])
                    ->hidden(fn (?CourseCategory $record) => $record === null),