In-Memory Sqlite and backup to disk

看代码更简单明了，在项目中引用System.Data.SQLite.dll时，看情况使用何种版本，下面代码测试时使用.netFx40 binary bundle win32版

            string cnstr = "Data Source=:memory:";
            SQLiteConnection cn = new SQLiteConnection(cnstr);
            cn.Open();

            string crtSql = "create table test (val int, str varchar(10))";
            SQLiteCommand cm = new SQLiteCommand(crtSql, cn);
            cm.ExecuteNonQuery();

            string insSql = "insert into test values (100, 'hello')";
            cm = new SQLiteCommand(insSql, cn);
            cm.ExecuteNonQuery();

            string cntSql = "select count(*) from test";
            cm = new SQLiteCommand(cntSql, cn);
            int count = Convert.ToInt32(cm.ExecuteScalar());
            Console.WriteLine(string.Format("count={0}", count));

            string sltSql = "select * from test";
            cm = new SQLiteCommand(sltSql, cn);
            SQLiteDataReader sdr = cm.ExecuteReader();
            while (sdr.Read())
            {
                Console.WriteLine(sdr.GetInt32(0).ToString());
                Console.WriteLine(sdr.GetString(1));
            }

            SQLiteConnection destcn = new SQLiteConnection(@"Data Source=G:\ProgramTest\test.db3");
            destcn.Open();
            cn.BackupDatabase(destcn, "main", "main", -1, null, 0);
            destcn.Close();

            cn.Close();