hardcode tables that can be imported by DataImporter (#540)

Author: Scott Bommarito

src/Stats.ImportAzureCdnStatistics/DataImporter.cs

@@ -10,6 +10,12 @@ namespace Stats.ImportAzureCdnStatistics
 {
     internal class DataImporter
     {
+        public enum Table
+        {
+            Fact_Dist_Download,
+            Fact_Download
+        }
+
         private readonly Func<Task<SqlConnection>> _openStatisticsSqlConnectionAsync;
         private const string _sqlSelectTop1FromTable = "SELECT TOP 1 * FROM [dbo].[{0}]";
 
@@ -18,8 +24,9 @@ public DataImporter(Func<Task<SqlConnection>> openStatisticsSqlConnectionAsync)
             _openStatisticsSqlConnectionAsync = openStatisticsSqlConnectionAsync;
         }
 
-        public async Task<DataTable> GetDataTableAsync(string tableName)
+        public async Task<DataTable> GetDataTableAsync(Table table)
         {
+            var tableName = table.ToString();
             var dataTable = new DataTable();
             var query = string.Format(_sqlSelectTop1FromTable, tableName);
 

src/Stats.ImportAzureCdnStatistics/Warehouse.cs

@@ -126,7 +126,7 @@ public async Task<DataTable> CreateAsync(IReadOnlyCollection<PackageStatistics>
 
             // create facts data rows by linking source data with dimensions
             var dataImporter = new DataImporter(_openStatisticsSqlConnectionAsync);
-            var factsDataTable = await dataImporter.GetDataTableAsync("Fact_Download");
+            var factsDataTable = await dataImporter.GetDataTableAsync(DataImporter.Table.Fact_Download);
 
             var knownOperationsAvailable = operations.Any();
             var knownClientsAvailable = clients.Any();
@@ -247,7 +247,7 @@ public async Task<DataTable> CreateAsync(IReadOnlyCollection<ToolStatistics> sou
 
             // create facts data rows by linking source data with dimensions
             var dataImporter = new DataImporter(_openStatisticsSqlConnectionAsync);
-            var dataTable = await dataImporter.GetDataTableAsync("Fact_Dist_Download");
+            var dataTable = await dataImporter.GetDataTableAsync(DataImporter.Table.Fact_Dist_Download);
 
             var knownClientsAvailable = clients.Any();
             var knownPlatformsAvailable = platforms.Any();