我从这篇博客文章中获得了帮助：

但是我发现com.mysql.jdbc.driver类未找到异常。那篇博客文章的不同之处在于，在我的案例中，他们尝试连接到mysql而不是MS
SQL。到目前为止，这是我的代码：package com.example.dbtry;

public class MainActivity extends Activity {
protected TextView tv;

private static final String url = "jdbc:jtds:sqlserver://Server.com:1433/DB_name";
private static final String user = "username";
private static final String pass = "password";



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    testDB();
}

public void testDB() {
    tv = (TextView)findViewById(R.id.textView1);
     try {
            Class.forName("com.mysql.jdbc.Driver");
            Connection con = DriverManager.getConnection(url, user, pass);
            /* System.out.println("Database connection success"); */

            String result = "Database connection success\n";
          tv.setText(result);
            Statement st = con.createStatement();
            ResultSet rs = st.executeQuery("select * from this_table");
            ResultSetMetaData rsmd = rs.getMetaData();

            while(rs.next()) {
                result += rsmd.getColumnName(1) + ": " + rs.getInt(1) + "\n";
                result += rsmd.getColumnName(2) + ": " + rs.getString(2) + "\n";
                result += rsmd.getColumnName(3) + ": " + rs.getString(3) + "\n";
            }
            tv.setText(result);
        }
        catch(Exception e) {
            e.printStackTrace();
            tv.setText(e.toString());
        }

    }


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

}

请告诉我我在做什么错。我还在清单中添加了对Internet的许可。