kql and sql fix when variable shared doesn't exist

src/Microsoft.DotNet.Interactive.Kql.Tests/KqlConnectionTests.cs

@@ -98,6 +98,34 @@ public async Task It_can_store_result_set_with_a_name()
                   .Which.Value.Should().BeAssignableTo<IEnumerable<TabularDataResource>>();
         }
 
+        [KqlFact]
+        public async Task When_variable_does_not_exist_then_an_error_is_returned()
+        {
+            var cluster = KqlFactAttribute.GetClusterForTests();
+            using var kernel = await CreateKernelAsync();
+            var result = await kernel.SubmitCodeAsync(
+                $"#!connect kql --kernel-name KustoHelp --cluster \"{cluster}\" --database \"Samples\"");
+
+
+            result.KernelEvents
+                .ToSubscribedList()
+                .Should()
+                .NotContainErrors();
+
+            var kqlKernel = kernel.FindKernelByName("kql-KustoHelp");
+
+            result = await kqlKernel.SendAsync(new RequestValue("my_data_result"));
+
+            using var events = result.KernelEvents.ToSubscribedList();
+
+            events.Should()
+                .ContainSingle<CommandFailed>()
+                .Which
+                .Message
+                .Should()
+                .Contain("Value 'my_data_result' not found in kernel kql-KustoHelp");
+        }
+
         [KqlFact]
         public async Task sending_query_to_kusto_will_generate_suggestions()
         {

src/Microsoft.DotNet.Interactive.SqlServer.Tests/MsSqlConnectionTests.cs

@@ -297,6 +297,34 @@ await kernel.SubmitCodeAsync($@"
                 .Be(1);
         }
 
+        [MsSqlFact]
+        public async Task When_variable_does_not_exist_then_an_error_is_returned()
+        {
+            var connectionString = MsSqlFactAttribute.GetConnectionStringForTests();
+            using var kernel = await CreateKernelAsync();
+            var result = await kernel.SubmitCodeAsync(
+                $"#!connect mssql --kernel-name adventureworks \"{connectionString}\"");
+
+
+            result.KernelEvents
+                .ToSubscribedList()
+                .Should()
+                .NotContainErrors();
+
+            var sqlKernel = kernel.FindKernelByName("sql-adventureworks");
+
+            result = await sqlKernel.SendAsync(new RequestValue("my_data_result"));
+
+            using var events = result.KernelEvents.ToSubscribedList();
+
+            events.Should()
+                .ContainSingle<CommandFailed>()
+                .Which
+                .Message
+                .Should()
+                .Contain("Value 'my_data_result' not found in kernel sql-adventureworks");
+        }
+
         [MsSqlFact]
         public async Task It_can_store_multiple_result_set_with_a_name()
         {

src/Microsoft.DotNet.Interactive.SqlServer/ToolsServiceKernel.cs

@@ -351,6 +351,10 @@ public Task HandleAsync(RequestValue command, KernelInvocationContext context)
             {
                 context.PublishValueProduced(command, value);
             }
+            else
+            {
+                context.Fail(command, message: $"Value '{command.Name}' not found in kernel {Name}");
+            }
 
             return Task.CompletedTask;
         }