June 2021
Intermediate to advanced
290 pages
9h 21m
Chinese
Content preview from Node与Express开发（第2版）
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price: Number,
tags: [String],
inSeason: Boolean,
available: Boolean,
requiresWaiver: Boolean,
maximumGuests: Number,
notes: String,
packagesSold: Number,
})
const Vacation = mongoose.model('Vacation', vacationSchema)
module.exports = Vacation
以上代码声明了度假产品模型的属性以及它们的类型。可以看到其中有几个字符串属性、
一些数值属性、两个布尔属性以及一个字符串数组（用
[String]
表示）。我们也可以给模式
定义方法。每个商品都有一个库存单位（
SKU
）
，虽然我们认为度假产品没有什么“库存”
可言，但从记账的角度来看，
SKU
是一个相当标准的概念，即便卖的不是有形的商品。
有了模式之后，使用
mongoose.model
来创建一个模型。在这一点上，
Vacation
跟传统的面
向对象编程中的类很相似。请注意，如果要定义方法，就必须在创建模型之前定义。
因为浮点数的本质，用
JavaScript
做财务计算时总是要十分小心。我们可以
把价格保存为美分而不是美元，这么做当然会有所帮助，但并不能完全解决
问题。对我们这个要求不高的旅游网站来说，倒是不用担心，但如果你的应
用涉及非常大或非常小的金额（例如，由利息或交易量带来的含小数的美分 ...
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.