C#操作Dataset数据集与SQLite数据库

近日有需要写点C#程序，有用到Dataset数据集和SQLite数据库，由于我从来就不擅长记各种编程语言的语法，所以在查阅一堆资料后，留下以下内容备忘：

    string datasource=Application.StartupPath + "\\test.db";
    System.Data.SQLite.SQLiteConnection.CreateFile(datasource);

    //连接数据库
    System.Data.SQLite.SQLiteConnection conn =
        new System.Data.SQLite.SQLiteConnection();
    System.Data.SQLite.SQLiteConnectionStringBuilder connstr =
        new System.Data.SQLite.SQLiteConnectionStringBuilder();
    connstr.DataSource = datasource;
    connstr.Password = "admin";//设置密码，SQLite ADO.NET实现了数据库密码保护
    conn.ConnectionString = connstr.ToString();
    conn.Open();

    //创建表
    System.Data.SQLite.SQLiteCommand cmd = new System.Data.SQLite.SQLiteCommand();
    string sql = "CREATE TABLE test(username varchar(20),password varchar(20))";
    cmd.CommandText=sql;
    cmd.Connection=conn;
    cmd.ExecuteNonQuery();

    //插入数据
    sql = "INSERT INTO test VALUES(‘dotnetthink‘,‘mypassword‘)";
    cmd.CommandText = sql;
    cmd.ExecuteNonQuery();

    //取出数据
    sql = "SELECT * FROM test";
    cmd.CommandText = sql;
    System.Data.SQLite.SQLiteDataReader reader = cmd.ExecuteReader();
    StringBuilder sb = new StringBuilder();
    while (reader.Read())
    {
        sb.Append("username:").Append(reader.GetString(0)).Append("\n")
            .Append("password:").Append(reader.GetString(1));
    }
    MessageBox.Show(sb.ToString());