docs(sample): add streaming queries with decimal conversion examples

Add CustomerSalesStreamingQuery demonstrating both direct and buffered streaming with decimal fields. Validates SqlDecimal conversion end-to-end.

Author: Per Kops

sample/Atc.Kusto.Sample/Atc.Kusto.Sample.csproj

@@ -12,6 +12,7 @@
     <None Remove="Queries\CustomersSplitByGenderQuery.kusto" />
     <None Remove="Queries\StormEventsQuery.kusto" />
     <None Remove="Queries\CustomersStreamingQuery.kusto" />
+    <None Remove="Queries\CustomerSalesStreamingQuery.kusto" />
   </ItemGroup>
 
   <ItemGroup>
@@ -20,6 +21,7 @@
     <EmbeddedResource Include="Queries\CustomersSplitByGenderQuery.kusto" />
     <EmbeddedResource Include="Queries\StormEventsQuery.kusto" />
     <EmbeddedResource Include="Queries\CustomersStreamingQuery.kusto" />
+    <EmbeddedResource Include="Queries\CustomerSalesStreamingQuery.kusto" />
   </ItemGroup>
 
   <ItemGroup>

sample/Atc.Kusto.Sample/Program.cs

@@ -190,6 +190,63 @@
     await warmupEnumerator.DisposeAsync();
 }
 
+// Demonstrate streaming with decimal conversion (CustomerSales has decimal fields)
+logger.LogInformation("Streaming customer sales (testing SqlDecimal to decimal conversion)...");
+var salesStreamingQuery = new CustomerSalesStreamingQuery();
+var salesCount = 0;
+
+await foreach (var sale in contosoSalesKustoProcessor.ExecuteStreamingQuery(salesStreamingQuery, CancellationToken.None))
+{
+    if (salesCount < 3)
+    {
+        // Log first 3 to verify decimal conversion works
+        logger.LogInformation(
+            "\tCustomer {CustomerName}: SalesAmount={SalesAmount:C}, TotalCost={TotalCost:C}",
+            sale.CustomerName,
+            sale.SalesAmount,  // SqlDecimal → decimal conversion via DataReaderExtensions!
+            sale.TotalCost);
+    }
+
+    salesCount++;
+}
+
+logger.LogInformation("Streamed {SalesCount} customer sales records with decimal values", salesCount);
+
+// Demonstrate buffered streaming with decimal conversion
+logger.LogInformation("Executing buffered streaming query for customer sales (testing SqlDecimal to decimal conversion)...");
+
+var salesBufferedResult = await contosoSalesKustoProcessor.ExecuteBufferedStreamingQuery(
+    salesStreamingQuery,
+    CancellationToken.None);
+
+if (salesBufferedResult is not null)
+{
+    var bufferedSalesCount = 0;
+    await foreach (var sale in salesBufferedResult.Rows.WithCancellation(CancellationToken.None))
+    {
+        if (bufferedSalesCount < 3)
+        {
+            // Log first 3 to verify decimal conversion works
+            logger.LogInformation(
+                "\tCustomer {CustomerName}: SalesAmount={SalesAmount:C}, TotalCost={TotalCost:C}",
+                sale.CustomerName,
+                sale.SalesAmount,  // SqlDecimal → decimal conversion via DataRowExtensions!
+                sale.TotalCost);
+        }
+
+        bufferedSalesCount++;
+    }
+
+    logger.LogInformation("Buffered streaming processed {BufferedSalesCount} records with decimals", bufferedSalesCount);
+
+    if (salesBufferedResult.Completion is not null)
+    {
+        logger.LogInformation(
+            "Sales streaming completion: HasErrors={HasErrors}",
+            salesBufferedResult.Completion.HasErrors);
+    }
+}
+
 // Demonstrate cancellation with server-side cancel enabled (default)
 logger.LogInformation("Demonstrating cancellation of a long-running streaming query (server-side cancel enabled)...");
 var rowCount = 0;

sample/Atc.Kusto.Sample/Queries/CustomerSalesQuery.kusto

@@ -4,5 +4,4 @@ Customers
 | summarize 
     SalesAmount = todecimal(round(sum(SalesAmount), 2)),
     TotalCost = todecimal(round(sum(TotalCost), 2))
-  by CustomerKey, CustomerName
-| take 100
+  by CustomerKey, CustomerName

sample/Atc.Kusto.Sample/Queries/CustomerSalesStreamingQuery.cs

@@ -0,0 +1,5 @@
+namespace Atc.Kusto.Sample.Queries;
+
+public record CustomerSalesStreamingQuery(
+    long? CustomerKey = null)
+    : KustoStreamingQuery<CustomerSales>;

sample/Atc.Kusto.Sample/Queries/CustomerSalesStreamingQuery.kusto

@@ -0,0 +1,12 @@
+declare query_parameters (
+    customerKey:long = long(null)
+);
+Customers
+| join kind=inner SalesFact on CustomerKey
+| where isnull(customerKey) or customerKey == CustomerKey
+| extend CustomerName = strcat(FirstName, ' ', LastName)
+| summarize
+    SalesAmount = todecimal(round(sum(SalesAmount), 2)),
+    TotalCost = todecimal(round(sum(TotalCost), 2))
+  by CustomerKey, CustomerName
+| take 100