用Sqlite Expert查询的时候，查询时间为：72ms，但是c#查询需要差不多2秒多！

查询语句如下：

public static DataSet Query(string SQLString)
        {
            using (SQLiteConnection connection = new SQLiteConnection(connectionString))
            {
                DataSet ds = new DataSet();
                try
                {
                    connection.Open();
                    SQLiteDataAdapter command = new SQLiteDataAdapter(SQLString, connection);
                    command.Fill(ds, "ds");
                }
                catch (System.Data.SQLite.SQLiteException ex)
                {
                    throw new Exception(ex.Message);
                }
                return ds;
            }
        }

查询时间调试：

Stopwatch st = new Stopwatch();
            st.Start();
            BLL.TestPaperDetail bll = new BLL.TestPaperDetail();
            DataSet ds = bll.GetTestPaperDis("TestPaperID=" + TestPaperID, Columns, "QuesType,Difficulty");
            st.Stop();

MessageBox.Show(st.Elapsed.ToString());

这个时候调试差不多2秒多；

但是把sql语句直接在sqlite Expert里面执行，只要70多毫秒！

求解！~！！！！