Question

我有2组代码。第一套我不认为为什么不起作用，但是第二套却不能。我必须创建对象的副本，添加希望添加的属性，保存到MongoDB中，然后最后删除旧对象。我有某种更好的方法被我忽略了吗？

订购模式：

const mongoose = require('mongoose');
const Schema = mongoose.Schema;

const orderSchema = new Schema({
    order_no: {
        type: String,
        minlength: 8,
        unique: true,
        required: true,
        validate(value) {
            if (value < 0) {
                throw new Error('less than zero.')
            }
        }
    },
    customer_no: {
        type: String,
        minlength: 8,
        unique: true,
        required: true,
        validate(value) {
            if (value < 0) {
                throw new Error('less than zero.')
            }
        }
    },
    invoice_no: {
        type: String,
        minlength: 8,
        unique: true,
        required: true,
        validate(value) {
            if (value < 0) {
                throw new Error('less than zero.')
            }
        }
    },
    lines: {
        type: Array,
        required: true
    },
    status: {
        type: String,
        required: true,
        default: 'Released'
    }
}, {
    timestamps: true
});

const Order = mongoose.model('Order', orderSchema);
module.exports = Order;

第一组：

try {
        const customer_no = request.params.id;
        const order = await Order.findOne({ customer_no });

        if (!order) {
            return response.status(404).send();
        }

        for (let i = 0; i < order.lines.length; i ++) {
            order.lines[i].updated_qty = order.lines[i].expected_qty;
        }

        await order.save();
        response.status(201);
        response.send(order);
    } catch (error) {
        response.status(500);
        response.send(error.message);
    }

第二组：

try {
        const customer_no = request.params.id;
        const current = await Order.findOne({ customer_no });

        if (!current) {
            return response.status(404).send();
        }

        const order = new Order({
            order_no: current.order_no,
            customer_no: current.customer_no,
            invoice_no: current.invoice_no,
            lines: current.lines
        });

        for (let i = 0; i < current.lines.length; i ++) {
            order.lines[i].updated_qty = current.lines[i].expected_qty;
        }

        await order.save();
        await current.delete();
        response.status(201);
        response.send(order);
    } catch (error) {
        response.status(500);
        response.send(error.message);
    }

我没有任何错误，第二组代码也可以使用，但是我希望第一组代码可以使用，因此我可以保留创建文档时的时间戳以及更新文档时的当前时间戳。

如何在MongoDB中保存修改后的对象

0 个答案: