光标索引超出界限异常 - Android SQLite

Question

我试图查询我的SQLite数据库，但我收到错误＆＃34;光标索引超出界限异常：请求索引0，大小为0＆＃34;。当我在SQLite Man中运行相同的查询时，我得到了我正在寻找的结果。

public int getHighScore () {

    String query = "SELECT score FROM " + SCORE_TABLE + ";";
    SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.rawQuery(query, null);
    cursor.moveToFirst();
    int score = cursor.getInt(0);
    cursor.close();
    return score;

}

Answer 1

请检查游标是否为空，然后您要从游标中获取记录。使用此行获取记录： 的 cursor.getInt（cursor.getColumnIndex（＆＃34;得分＆＃34;）））

使用此代码：

public int getHighScore () {
int score=0;
    String query = "SELECT score FROM " + SCORE_TABLE + ";";
    SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.rawQuery(query, null);
   if (cursor != null && cursor.moveToFirst()) {
     score = cursor.getInt(cursor.getColumnIndex("score")));
}
    cursor.close();
    return score;

}