WIP for query execution

src/Microsoft.SqlTools.ServiceLayer/QueryExecutionServices/Query.cs

@@ -0,0 +1,69 @@
+using System;
+using System.Collections.Generic;
+using System.Data;
+using System.Data.Common;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.SqlTools.ServiceLayer.QueryExecutionServices.Contracts;
+
+namespace Microsoft.SqlTools.ServiceLayer.QueryExecutionServices
+{
+    public class Query //: IDisposable
+    {
+        public string QueryText { get; set; }
+
+        public DbConnection SqlConnection { get; set; }
+
+        private readonly CancellationTokenSource cancellationSource;
+
+        public List<ResultSet> ResultSets { get; set; }
+
+        public Query(string queryText, DbConnection connection)
+        {
+            QueryText = queryText;
+            SqlConnection = connection;
+            ResultSets = new List<ResultSet>();
+            cancellationSource = new CancellationTokenSource();
+        }
+
+        public async Task Execute()
+        {
+            // Open the connection, if it's not already open
+            if ((SqlConnection.State & ConnectionState.Open) == 0)
+            {
+                await SqlConnection.OpenAsync(cancellationSource.Token);
+            }
+
+            // Create a command that we'll use for executing the query
+            using (DbCommand command = SqlConnection.CreateCommand())
+            {
+                command.CommandText = QueryText;
+                command.CommandType = CommandType.Text;
+
+                // Execute the command to get back a reader
+                using (DbDataReader reader = await command.ExecuteReaderAsync(cancellationSource.Token))
+                {
+                    do
+                    {
+                        // Create a new result set that we'll use to store all the data
+                        ResultSet resultSet = new ResultSet();
+                        if (reader.CanGetColumnSchema())
+                        {
+                            resultSet.Columns = reader.GetColumnSchema().ToArray();
+                        }
+
+                        // Read until we hit the end of the result set
+                        while (await reader.ReadAsync(cancellationSource.Token))
+                        {
+                            resultSet.AddRow(reader);
+                        }
+
+                        // Add the result set to the results of the query
+                        ResultSets.Add(resultSet);
+                    } while (await reader.NextResultAsync(cancellationSource.Token));
+                }
+            }
+        }
+    }
+}