android 将sql查询结果保存为游标异常

Question

我对那段代码有一个小问题：

public static int localUserIdByServerUserId(int serverUserId, String serverName){

        dbHelper = new DataBaseHelper(context, "opalqnka_sys_tpl.sqlite", null, 1);
        dbHelper.getDatabase();
        dbHelper.executeQuery("users", "objectId", "2");
        dbHelper.executeQuery("users","serverName","opalqnka");
        dbHelper.executeQuery("users", "objectId", "3");
        dbHelper.executeQuery("users","serverName","opalqnka");
        dbHelper.executeQuery("users", "objectId", "3");

        String query = "SELECT id FROM users WHERE objectId = "+serverUserId+" AND serverName = '"+serverName+"' LIMIT 1";
        ArrayList<String> result = new ArrayList<String>();
        cursor = dbHelper.executeSQLQuery(query);
        cursor.moveToFirst();
        while(!cursor.isAfterLast()) {
            result.add(cursor.getString(cursor.getColumnIndex("id")));
             cursor.moveToNext();
        }

        int uuid = Integer.parseInt(result.get(cursor.getInt(cursor.getColumnIndex("id"))));
        Log.w("localUSerByIdServerUserId","LocalUserByIdServerUserId result : "+uuid);
        cursor.close();
        return uuid;
    }

它向我抛出一个 android.database.CursorIndexOutOfBoundsException: Index 0 requests, with a size of 0 在这一行：

int uuid = Integer.parseInt(result.get(cursor.getInt(cursor.getColumnIndex("id"))));

我不太熟悉数据库为什么我在这里问也许很愚蠢的问题。 因此，如果有人能解决我的问题，请提前致谢！

Answer 1

首先明确自己想要什么。
崩溃问题是因为没有得到任何结果值而发生的。
首先检查结果中添加的记录。像这样打印日志

Log.e("",""+result.toString());

如果只有一条记录，您可以这样得到：

int uuid = Integer.parseInt(result.get(0));

如果有不止一条记录，您可以使用 for 循环并获取多个 id：

for(int i=0; i<result.size();i++)
    int uuid = Integer.parseInt(result.get(i));

Answer 2

你可以这样做：

cursor.moveToFirst();
    while(!cursor.isAfterLast()) {
        result.add(cursor.getString(cursor.getColumnIndex("id")));
        cursor.moveToNext();
    }

    Log.i("result ","Result : "+result.toString());
    Log.i("CURSOR ","Cursor Position : "+cursor.getPosition());
    Integer uuid = Integer.parseInt(result.get(cursor.getColumnIndex("id")));