我有游标的问题在我的Android应用程序。 我有一个SQLiteDatabase返回我的光标,当我尝试用获取的值:
I have problems with Cursor in my Android application. I have a SQLiteDatabase that return me Cursor when I try to fetch the values with :
public Cursor fetchOption(long rowId) throws SQLException { Cursor mCursor = mDb.query(true, DATABASE_TABLE, new String[] {KEY_ROWID, KEY_TITLE, KEY_BODY}, KEY_ROWID + "=" + rowId, null, null, null, null, null); if (mCursor != null) { mCursor.moveToFirst(); } return mCursor; }
但我不知道如何获取光标的字段的值。 如果我这样做:
But I don't know how to obtain the value of the field in the Cursor. If I do that :
String a = mOptionDb.fetchOption(0).getColumnName(0).toString(); String b = mOptionDb.fetchOption(0).getColumnName(1).toString(); String c = mOptionDb.fetchOption(0).getColumnName(2).toString();
予得到的列(_id,标题,正文),但不是值的名称。 我该如何解决?
I obtain the name of the columns (_id, title, body) but not the value. How can I resolve that?
感谢你提前为您解答。 迈克尔
Thank you in advance for your answer. Michaël
推荐答案我想你可以忘记检查空。
I think you can forget about checking for null.
相反,检查是否有数据,然后使用光标访问的列:
Instead check if there is data and then access the columns using the cursor:
Cursor cursor = fetchOption(0); if (cursor.moveToFirst()) // data? System.out.println(cursor.getString(cursor.getColumnIndex("title")); cursor.close(); // that's important too, otherwise you're gonna leak cursors
这也可能是有意义的阅读机器人教程。记事本教程似乎符合这个要求:developer.android/guide/tutorials/notepad/index.html
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光标:获取字段值(安卓)
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