如何插入或更新数据库行的特定字段？

Question

我在我的Android应用程序中使用数据库表。 我想做的是如果不存在则插入行，否则在其中更新条目？ 我正在使用以下代码，但没有发现运气。

public boolean insertIntoOrder(String couponBrand, String couponTitle, String couponDenomination, int couponCount) {
        database = this.getWritableDatabase();
        ContentValues orderContentValues = new ContentValues();
        orderContentValues.put(KEY_ORDER_BRAND, couponBrand);
        orderContentValues.put(KEY_ORDER_TITLE, couponTitle);
        orderContentValues.put(KEY_ORDER_DENOMINATION, couponDenomination);
        orderContentValues.put(KEY_ORDER_COUPON_COUNT, couponCount);
        boolean responseValue = checkOrderConfirmation(couponBrand, couponTitle, couponDenomination);
        if (responseValue == true) {
            database.insert(TABLE_ORDER_CONFIRMATION, null, orderContentValues);
        }
        else {
            couponCount = couponCount++;
            database.execSQL("UPDATE " + TABLE_ORDER_CONFIRMATION + " SET " + KEY_ORDER_COUPON_COUNT + " = ? WHERE " + KEY_ORDER_BRAND + " = ? AND " + KEY_ORDER_TITLE + " = ? AND " + KEY_ORDER_DENOMINATION + " = ?", new String[] {couponCount + "", couponBrand, couponTitle, couponDenomination});
        }
        return true;
    }

public boolean checkOrder(String couponBrand, String couponTitle, String couponDenomination) {
        database = this.getReadableDatabase();
        try {
            checkOrderConfirmationCursor = database.rawQuery("SELECT * FROM " + TABLE_ORDER_CONFIRMATION + " WHERE " + KEY_ORDER_BRAND + " = ? AND " + KEY_ORDER_TITLE + " = ? AND " + KEY_ORDER_DENOMINATION + " = ?", new String[] {couponBrand, couponTitle, couponDenomination});

            if (checkOrderConfirmationCursor == null) {
                if (checkOrderConfirmationCursor.getCount() <= 0) {
                }
            }
            else {
                return true;
            }
        }
        catch (SQLiteException sqle) {
            sqle.printStackTrace();
        }
        return false;
    }

我想更新优惠券计数，如果新行包含重复的数据，但没有任何帮助。 任何帮助将是可观的。 提前致谢。

Answer 1

尝试将checkOrder更改为：

public boolean checkOrder(String couponBrand, String couponTitle, String couponDenomination) {
    database = this.getReadableDatabase();
    try {
        Cursor checkOrderConfirmationCursor = database.rawQuery("SELECT * FROM " + TABLE_ORDER_CONFIRMATION + " WHERE " + KEY_ORDER_BRAND + " = ? AND " + KEY_ORDER_TITLE + " = ? AND " + KEY_ORDER_DENOMINATION + " = ?", new String[] {couponBrand, couponTitle, couponDenomination});

        if (checkOrderConfirmationCursor != null
                && checkOrderConfirmationCursor.getCount() > 0) {
            return true
        }
    }
    catch (SQLiteException sqle) {
        sqle.printStackTrace();
    }
    return false;
}

另外，您的主要方法是调用checkOrderConfirmation但是该方法名为checkOrder ...