MongoDB快速上手指南： 使用 Mocha 编写测试 “Test Driven Development”
Mocha 是一个 js 测试的包, 编写测试有两个关键字 describe 和 it
describe是一个”统领块”, 所有的 test functions 都会在它”名下”it表示每一个 test function
create_test.jsconst assert = require('assert')// assume we have a User model defined in src/user.jsconst User = require('../src/user')// after installing Mocha, we have global access// to describe and it keywordsdescribe('Creating records', () => {
it('saves a user', () => {const joe = new User({ name: "Joe" });
joe.save();assert()
});
});复制代码NoSQL Databases
Benefits of NoSQL
- Easy for inserting and retrieving data, since they are contained in one block, in one json object
- Flexible schema, if a new attribute added, it is easy to just add / append to the object
- Scalability, horizontally partition the data (availability > consistency)
- Aggregation, find metrics and etc
Drawbacks of NoSQL
- Update = Delete + Insert, not built for update
- Not consistent, ACID is not guaranteed, do not support transactions
- Not read optimized. Read entire block find the attribute. But SQL, just need one column (read time compartively slow)
- Relations are not implicit
- JOINS are hard to accomplish, all manually
作者：是小梁同学呀
来源：稀土掘金
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