Question

所以我有一个SQLite数据库，其列有stop_number，stop_lat和stop_lon。我找不到关于如何搜索停止号并返回相应的stop_lat和stop_lon的连贯答案？我已经尝试了几种查询命令，但我似乎无法正确使用它。对数据基础新手的任何帮助？

Answer 1

尝试类似

的内容

Cursor cursor = mDatabase.query(   TABLE_STOP,
                            new String[] { KEY_STOP_LAT, KEY_STOP_LONG },
                            KEY_STOP_NUMBER + "=?",
                            new String[] { <your stop number as string> },
                            null,
                            null,
                            null);

if(cursor.getCount()>0){

    cursor.moveToFirst();

    float stop_lat = cursor.getFloat(0); // first column requested in the second query argument
    float stop_long = cursor.getFloat(1); // second column requested in the second query argument
}

cursor.close();

文档here。

Answer 2

尝试运行此查询。我在我的案子里工作过。

        DataBaseHelper databaseManager = new DataBaseHelper(this);
        databaseManager.openDataBase();
       SQLiteDatabase   db = databaseManager.getWritableDatabase();
        uCursor = db.rawQuery("select distinct stop_number from tablename", null);
        if(uCursor != null && uCursor.getCount() > 0) {
            while (uCursor.moveToNext()) {
                String stop_number = uCursor.getString(uCursor.getColumnIndex("stop_number"));
                Cursor cursor = db.rawQuery("select distinct stop_lang, stop_lat from table where stop_number = "+stop_number, null);
                if(cursor != null && cursor.getCount() > 0) {
                    while (cursor.moveToNext()) {
                        String stop_lang = cursor.getString(cursor.getColumnIndex("stop_lang"));
                        String stop_lat = cursor.getString(cursor.getColumnIndex("stop_lat"));

                    }
                }

            }
        }

Android SQLite数据库并返回一列

2 个答案: