public object BulkMerge(IEnumerable <TEntity> entities) { var entity = entities.FirstOrDefault(); if (entity is Customers) { _dbContext.BulkMerge <Customers>(entities, options => options.ColumnPrimaryKeyExpression = customer => customer.IdCustomer); } if (entity is Products) { _dbContext.BulkMerge <Products>(entities, options => options.ColumnPrimaryKeyExpression = product => product.IdProduct); } if (entity is Invoices) { _dbContext.BulkMerge <Invoices>(entities, options => options.ColumnPrimaryKeyExpression = invoice => invoice.IdInvoice); } if (entity is InvoiceDetails) { _dbContext.BulkMerge <InvoiceDetails>(entities, options => options.ColumnPrimaryKeyExpression = d => d.Id); } if (entity is VendorVisits) { _dbContext.BulkMerge <VendorVisits>(entities, options => options.ColumnPrimaryKeyExpression = visit => visit.IdVendorVisit); } if (entity is DeliveryOrders) { _dbContext.BulkMerge <DeliveryOrders>(entities, options => options.ColumnPrimaryKeyExpression = delivery => delivery.IdDelivery); } return(1); }