这是我的问题:
Cursor nextdate(String Date) {
SQLiteDatabase db = this.getReadableDatabase();
String[] params = new String[]{String.valueOf(Date)};
Cursor cur = db.rawQuery(" SELECT MIN (" + colDateDue + ") FROM " + PAYMENTS + " WHERE " + colDateDue + ">=?", params);
cur.moveToFirst();
return cur;
}
我想在textview中显示查询的结果,但是我不知道如何显示,所以我自然会寻找答案。我找到了几个答案,然后得出了这个结论:
DatabaseHelper db = new DatabaseHelper(this);
String str = "";
if (c!= null) {
if (c.moveToFirst()) {
str = c.getString(c.getColumnIndex(db.colDateDue);
}
}
TextView.setText(str);
但我明白了
Caused by: java.lang.IllegalStateException: Couldn't read row 0, col -1 from CursorWindow. Make sure the Cursor is initialized correctly before accessing data from it.
这让我有点困惑,因为通常的错误修复方法是使用
cur.moveToFirst();
这两种情况下都使用…我到底做错了什么? 最佳答案
这样试试:
将列索引保留为0,因为该游标将只有一列。
DatabaseHelper db = new DatabaseHelper(this);
String str = "";
if (c!= null) {
if (c.moveToFirst()) {
str = c.getString(0);
}
}
TextView.setText(str);