Implementing Pagination with Filtering in ASP.NET Core MVC and Entity Framework
I'm working on a personal project and I'm relatively new to this, so bear with me... I'm currently working on an ASP.NET Core MVC application (version 6.0) that fetches data from a SQL Server database using Entity Framework Core (version 6.0). I need to implement pagination along with filtering, but I'm running into some unexpected behavior. I've set up a basic repository pattern and I'm trying to fetch a paginated list of products based on some filter criteria (like category and price range). The filtering part works fine individually, but when I combine pagination with filtering, it seems to give incorrect results or even throws an exception. Here’s a snippet of my repository method: ```csharp public async Task<PaginatedList<Product>> GetProductsAsync(string category, decimal? minPrice, decimal? maxPrice, int pageIndex, int pageSize) { IQueryable<Product> query = _context.Products; if (!string.IsNullOrEmpty(category)) { query = query.Where(p => p.Category == category); } if (minPrice.HasValue) { query = query.Where(p => p.Price >= minPrice.Value); } if (maxPrice.HasValue) { query = query.Where(p => p.Price <= maxPrice.Value); } return await PaginatedList<Product>.CreateAsync(query.AsNoTracking(), pageIndex, pageSize); } ``` And here’s how I’m calling this method from my controller: ```csharp public async Task<IActionResult> Index(string category, decimal? minPrice, decimal? maxPrice, int? pageIndex) { int pageSize = 10; var products = await _productRepository.GetProductsAsync(category, minPrice, maxPrice, pageIndex ?? 1, pageSize); return View(products); } ``` The exception I get is `InvalidOperationException: The query must be a non-tracking query if 'AsNoTracking' is applied to 'IQueryable'`. I also noticed that when I paginate through the products, the count of total products doesn’t reflect my filters correctly, which confuses the pagination links. I did some debugging and verified that my filters are applied before I call the `PaginatedList.CreateAsync()` method, but it seems that the issue arises when counting the total items for pagination. Any insights on how to fix this or best practices for implementing pagination with filtering in this scenario? My development environment is Ubuntu. Thanks in advance! Any ideas what could be causing this?