Npgsql: Improve SystemQueryExample

Author: amotl

by-language/csharp-npgsql/DemoProgram.cs

@@ -57,15 +57,19 @@ public static async Task<List<string>> SystemQueryExample(NpgsqlConnection conn)
         {
             Console.WriteLine("Running SystemQueryExample");
             var mountains = new List<string>();
-            await using (var cmd = new NpgsqlCommand("SELECT mountain FROM sys.summits ORDER BY 1 LIMIT 25", conn))
+            const string sql = "SELECT mountain, height, coordinates FROM sys.summits ORDER BY height DESC LIMIT 25";
+            await using (var cmd = new NpgsqlCommand(sql, conn))
             await using (var reader = cmd.ExecuteReader())
             {
                 while (await reader.ReadAsync())
                 {
-                    mountains.Add(reader.GetString(0));
+                    mountains.Add(
+                        reader["mountain"].ToString() + " - " +
+                        reader["height"].ToString() + " - " +
+                        reader["coordinates"].ToString());
                 }
 
-                Console.WriteLine($"Mountains: {string.Join(",", mountains)}");
+                Console.WriteLine($"Mountains:\n{string.Join("\n", mountains)}");
             }
 
             Console.WriteLine();

by-language/csharp-npgsql/tests/DemoProgramTest.cs

@@ -6,7 +6,7 @@
 
 namespace demo.tests
 {
-    
+
     public class DatabaseFixture : IDisposable
     {
         public NpgsqlConnection Db { get; private set; }
@@ -29,10 +29,10 @@ public void Dispose()
         }
 
     }
-    
+
     public class DemoProgramTest : IClassFixture<DatabaseFixture>
     {
-        
+
         DatabaseFixture fixture;
         DatabaseWorkloads program = new DatabaseWorkloads();
 
@@ -51,7 +51,7 @@ public async Task TestSystemQueryExample()
             var mountains = await task.WaitAsync(TimeSpan.FromSeconds(0.5));
 
             // Check results.
-            Assert.Equal("Acherkogel", mountains[0]);
+            Assert.Equal("Mont Blanc - 4808 - (6.86444,45.8325)", mountains[0]);
         }
 
         [Fact]
@@ -79,6 +79,5 @@ public async Task TestUnnestExample()
             // Check results.
             Assert.Equal(10, resultCount);
         }
-        
     }
 }