java - 游标上的 IllegalStateException

Question

尝试从 SQLite 数据库读取时出现此错误

IllegalStateException: Couldn't read row 0, col -1 from CursorWindow. Make sure the Cursor is initialized correctly before accessing data from it.

DbHelper dbHelper = new DbHelper(this);
SQLiteDatabase database = dbHelper.getWritableDatabase();
Cursor cursor = dbHelper.readNumber(database);

String ItemId;

if (cursor.getCount() > 0) {
    while (cursor.moveToNext()) {
        //getting the ERROR here
        ItemId = cursor.getString(cursor.getColumnIndex(DbContract.ITEMID));
        number = cursor.getString(cursor.getColumnIndex(DbContract.PHONE_NUMBER));
        callType = cursor.getString(cursor.getColumnIndex(DbContract.CALL_TYPE));
        callDate = cursor.getString(cursor.getColumnIndex(DbContract.CALL_DATE));
        callDuration = cursor.getString(cursor.getColumnIndex(DbContract.CALL_DURATION));

        arrayList.add(new PhNumber(ItemId, number, callType, callDate, callDuration));
        if (debug) {
            Log.i(TAG, "DATA FOUND IN DB:\n" + "\t ID: " + ItemId + ", Number: " + number + "\n");
        }
    }
    cursor.close();
    dbHelper.close();
    result = true;
    if (debug) {
        Log.d(TAG, " Number of items in DB: " + arrayList.size());
    }
} 

读号

public Cursor readNumber(SQLiteDatabase database) {
    String[] projections = {"id", DbContract.PHONE_NUMBER};
    return (database.query(DbContract.TABLE_NAME, projections, null, null, null, null, null));
}

这是我的数据库

private static final String CREATE = "create table " + DbContract.TABLE_NAME +
        "(id integer primary key autoincrement,"
        + DbContract.ITEMID + " text, "
        + DbContract.PHONE_NUMBER + " text, "
        + DbContract.CALL_TYPE + " text, "
        + DbContract.CALL_DATE + " text, "
        + DbContract.CALL_DURATION + " text, "
        + DbContract.SYNC_STATUS + " text)";

Answer 1

在您的投影中，由 readNumber 调用创建，您只有 id 和 PHONE_NUMBER 返回列。可能 DbContract.ITEMID 不等于 id 并且在尝试查找游标中的 DbContract.ITEMID 时未找到它。要解决此问题，您需要在 readNumber 方法中使用 ITEMID，例如:

public Cursor readNumber(SQLiteDatabase database) {
    String[] projections = {DbContract.ITEMID, DbContract.PHONE_NUMBER};
    return (database.query(DbContract.TABLE_NAME, projections, null, null, null, null, null));
}

另一个问题是您也在尝试访问其他字段，例如:CALL_TYPE、CALL_DATE 等。

因此，为了解决问题，您可以:

• 不要尝试检索不属于结果的字段。
• 也在投影中添加所需的字段。