android.database.sqlite.SQLiteDatabase.rawQuery（）不更新DATETIME列了SQLite的日期时间（）函数 [英] android.database.sqlite.SQLiteDatabase.rawQuery() is not updating a DATETIME column with a SQLite datetime() function

问题描述

public Cursor set_datetime_next(Reminder r) {       
    String _newVal = "datetime('now', '+7 days')";
    String[] args = { new Integer(r.getID()).toString() };
    String query =
        "UPDATE " + DBConst.TABLE
      + " SET "   + DBConst.f_DATETIME_NEXT + "=" + _newVal
      + " WHERE " + DBConst.f_ID +"=?";
    Log.i(TAG, query);
    return db.rawQuery(query, args);
}

我也试图通过在 DATETIME（'现在'，'7天'）作为绑定参数，这是行不通的，因为的Android文档说：

I have also tried passing in datetime('now', '+7 days') as a bound parameter, that will not work, as the Android documentation says:

该值将被绑定为字符串。

The values will be bound as Strings.

参考文献：

• <一个href="http://developer.android.com/reference/android/database/sqlite/SQLiteDatabase.html">http://developer.android.com/reference/android/database/sqlite/SQLiteDatabase.html
• http://www.sqlite.org/lang_datefunc.html

• http://developer.android.com/reference/android/database/sqlite/SQLiteDatabase.html
• http://www.sqlite.org/lang_datefunc.html

推荐答案

游标未关闭。

public void set_datetime_next(Reminder r, String _newVal) {     
    String[] args = { new Integer(r.getID()).toString() };
    String query =
        "UPDATE " + DBConst.TABLE
      + " SET "   + DBConst.f_DATETIME_NEXT + "=" + _newVal
      + " WHERE " + DBConst.f_ID +"=?";
    Log.i(TAG, query);
    Cursor cu = db.rawQuery(query, args);
    cu.moveToFirst();
    cu.close();     
}

尽管这是有道理的，真正困扰我的是调用的要求 moveToFirst（）（或其他一些功能，将光标以某种方式的工作） 。照片 如果没有调用这两个 moveToFirst（）和关闭（），该行一直没有更新。 关闭（）本身在 rawQuery（），什么也没做。

While that makes sense, what really puzzles me is the requirement of calling moveToFirst() (or some other function which would "work with" the cursor in some way).
Without the call to both moveToFirst() and close(), the row was never updated. close() by itself, after the rawQuery(), did nothing.

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