.NET Core web API + Dapper – QueryMultiple

Returning multiple recordsets

My current “day job” is building applications for managing portfolios of foreign currency instruments. A portfolio can contain many different types of instrument (Forwards, Options, Swaps etc.). One of the “optimisations” we use is retrieving all the different types of instruments in a portfolio with one stored procedure call.

SQL Server Management Studio Dependency viewer

The closest scenario I could come up with using the World Wide Importers database was retrieving a summary of all the information associated with an Invoice for display on a single screen.

CREATE PROCEDURE [Sales].[InvoiceSummaryGetV1](@InvoiceID as int)

SELECT [InvoiceID]
--        ,[CustomerID]
--        ,[BillToCustomerID]
--        ,[ContactPersonID]
--        ,[AccountsPersonID]
		,[SalespersonPersonID] as SalesPersonID
		,[SalesPerson].[PreferredName] as SalesPersonName
--        ,[PackedByPersonID]
--        ,[InternalComments]
--        ,[TotalDryItems]
--        ,[TotalChillerItems]
		,[RunPosition] as DeliveryRunPosition
		,[ReturnedDeliveryData] as DeliveryData
		,[ConfirmedDeliveryTime] as DeliveredAt
		,[ConfirmedReceivedBy] as DeliveredTo
--        ,[LastEditedBy]
--        ,[LastEditedWhen]
	FROM [Sales].[Invoices]
	INNER JOIN [Application].[People] as SalesPerson ON (Invoices.[SalespersonPersonID] = [SalesPerson].[PersonID])
	INNER JOIN [Application].[DeliveryMethods] as DeliveryMethod ON (Invoices.[DeliveryMethodID] = DeliveryMethod.[DeliveryMethodID])
WHERE ([Invoices].[InvoiceID] = @InvoiceID)

SELECT [InvoiceLineID]
      ,[Description] as StockItemDescription
--      ,[LineProfit]
--      ,[LastEditedBy]
--      ,[LastEditedWhen]
	FROM [Sales].[InvoiceLines]
		INNER JOIN [Warehouse].[PackageTypes] as PackageType ON ([PackageType].[PackageTypeID] = [InvoiceLines].[PackageTypeID])
WHERE ([InvoiceLines].[InvoiceID] = @InvoiceID)

SELECT [StockItemTransactionID]
      ,StockItem.[StockItemName] as StockItemName
--      ,[CustomerID]
--      ,[InvoiceID]
--      ,[SupplierID]
--      ,[PurchaseOrderID]
      ,[TransactionOccurredWhen] as TransactionAt
--      ,[LastEditedBy]
--      ,[LastEditedWhen]
	FROM [Warehouse].[StockItemTransactions]
	INNER JOIN [Warehouse].[StockItems] as StockItem ON ([StockItemTransactions].StockItemID = [StockItem].StockItemID)
	INNER JOIN [Application].[TransactionTypes] as TransactionType ON ([StockItemTransactions].[TransactionTypeID] = TransactionType.[TransactionTypeID])
	WHERE ([StockItemTransactions].[InvoiceID] = @InvoiceID)


The stored procedure returns 3 recordsets, a “summary” of the Order, a summary of the associated OrderLines and a summary of the associated StockItemTransactions.

public async Task<ActionResult<Model.InvoiceSummaryGetDtoV1>>Get([Range(1, int.MaxValue, ErrorMessage = "Invoice id must greater than 0")] int id)
	Model.InvoiceSummaryGetDtoV1 response = null;

		using (SqlConnection db = new SqlConnection(this.connectionString))
			var invoiceSummary = await db.QueryMultipleWithRetryAsync("[Sales].[InvoiceSummaryGetV1]", param: new { InvoiceId = id }, commandType: CommandType.StoredProcedure);

			response = await invoiceSummary.ReadSingleOrDefaultWithRetryAsync<Model.InvoiceSummaryGetDtoV1>();
			if (response == default)
				logger.LogInformation("Invoice:{0} not found", id);

				return this.NotFound($"Invoice:{id} not found");

			response.InvoiceLines = (await invoiceSummary.ReadWithRetryAsync<Model.InvoiceLineSummaryListDtoV1>()).ToArray();

			response.StockItemTransactions = (await invoiceSummary.ReadWithRetryAsync<Model.StockItemTransactionSummaryListDtoV1>()).ToArray();
	catch (SqlException ex)
		logger.LogError(ex, "Retrieving Invoice, Invoice Lines or Stock Item Transactions");

		return this.StatusCode(StatusCodes.Status500InternalServerError);

	return this.Ok(response);

I use Google Chrome, Mozilla Firefox, Microsoft Edgeium, and Opera but the screen capture was done with FireFox mainly because it formats the Java Script Object Notation(JSON) response payloads nicely.

FireFox displaying Invoice Summary response

I had to extend the DapperTransient module to add SqlMapper extension (plus all the different overloads) retry methods.

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