mongoose提供如下的crud方法

    • save
    • find | findOne
    • update
    • remove

    下面我们使用user模型为例，给出具体例子

    文档

    具体代码

    2.   username: 'i5ting',
    3.   password: '0123456789'
    4. });
    6. user.save((err, u) => {
    7.     t.false(err);
    8.     t.is(u.username, 'i5ting');
    9. });

    读取(Retrieve)

    find：根据条件查询，返回的是数组

    1. Model.find(conditions, [fields], [options], [callback])
    3. Finds documents
    5. Parameters:
    7. - conditions <Object>
    8. - [fields] <Object> optional fields to select
    9. - [options] <Object> optional
    10. - [callback] <Function>
    12. Returns:
    13.     <Query>

    代码

    1. User.find({}, (err, docs) => {
    2.     t.false(err);
    3.     t.is(docs.length, 1);
    4.     t.is(docs[0].username, 'i5ting');
    5. });

    findOne：根据条件查询，返回的是一条数据对象

    文档

    1. Model.findOne([conditions], [fields], [options], [callback])
    3. Finds one document.
    5. Parameters:
    7. - [conditions] <Object>
    8. - [fields] <Object> optional fields to select
    9. - [options] <Object> optional
    10. - [callback] <Function>
    12.     <Query>

    代码

    findByIdAndUpdate：根据ID查找并更新

    文档说明如下

    1. Model.findByIdAndUpdate(id, [update], [options], [callback])
    3. Issues a mongodb findAndModify update command by a documents id.
    5. show code
    7. Parameters:
    9. - id <ObjectId, HexId> an ObjectId or string that can be cast to one.
    11. - [options] <Object>
    12. - [callback] <Function>
    14. Returns:
    16.     <Query>
    1.  User.findByIdAndUpdate(u._id, {
    2.     username: 'sang',
    3. }, (err, user) => {
    4.     t.false(err);
    5.     t.is(user.username, 'sang');
    6. });

    findOneAndUpdate：根据查询条件查找并更新

    1. Model.findOneAndUpdate([conditions], [update], [options], [callback])
    3. Issues a mongodb findAndModify update command.
    5. Parameters:
    7. - [conditions] <Object>
    8. - [update] <Object>
    9. - [options] <Object>
    10. - [callback] <Function>
    12. Returns:
    13.     <Query>

    具体代码

    1. User.findOneAndUpdate({
    2.     username: 'i5ting for update 2',
    3. }, {
    4.     username: 'sang',
    5. }, (err, user) => {
    6.     t.false(err);
    7.     t.is(user.username, 'sang');
    8. });

    删除(Delete)

    文档

    代码

    1. User.remove({username: 'i5ting for delete'}, (err, doc) => {
    2.     t.false(err);
    3.     t.is(doc.result.ok, 1);
    4.     t.is(doc.result.n, 1);
    5. });
    1. $ cd db
    2. $ npm test
    4. > ava crud -v
    7. 数据库连接成功
    8.   ✔ #save()
    9.   ✔ #find() return array
    11.   ✔ #findOne() return user obj
    12.   ✔ #remove()
    13.   ✔ #findByIdAndUpdate()
    14.   ✔ #findOneAndUpdate()
    16.   6 tests passed

    调试模式

    调试模式是mongoose提供的一个非常实用的功能，用于查看mongoose模块对mongodb操作的日志，一般开发时会打开此功能，以便更好的了解和优化对mongodb的操作。

    1. var mongoose = require("mongoose");
    3. // 核心代码，是否开启测试
    4. mongoose.set('debug', true);
    6. var db = mongoose.connect("mongodb://127.0.0.1:27017/db_helloworld"); 
    8. db.connection.on("error", function (error) {  
    9.   console.log("数据库连接失败：" + error); 
    10. }); 
    12. db.connection.on("open", function () {  
    13.   console.log("数据库连接成功");
    14. });

    执行测试如下

    1. $ cd db
    2. $ npm test
    4. > koa-db@1.0.0 test /Users/sang/workspace/17koa/book-source/db
    5. > ava crud -v
    8. 数据库连接成功
    9. Mongoose: users.remove({}) {}  
    10.   ✔ #save()
    11.   ✔ #find() return array
    12.   ✔ #findById() return array
    13.   ✔ #findOne() return user obj
    14.   ✔ #remove()
    15.   ✔ #findByIdAndUpdate()
    16.   ✔ #findOneAndUpdate()
    17. Mongoose: users.insert({ username: 'i5ting', password: '0123456789', _id: ObjectId("5734490640caa6d36906b8d4"), __v: 0 })   
    18. Mongoose: users.find({}) { fields: undefined }  
    19. Mongoose: users.findOne({ username: 'i5ting' }) { fields: undefined }  
    20. Mongoose: users.insert({ username: 'i5ting for delete', password: '0123456789', _id: ObjectId("5734490640caa6d36906b8d5"), __v: 0 })   
    21. Mongoose: users.insert({ username: 'i5ting for update 1', password: '0123456789', _id: ObjectId("5734490640caa6d36906b8d6"), __v: 0 })   
    22. Mongoose: users.insert({ username: 'i5ting for update 2', password: '0123456789', _id: ObjectId("5734490640caa6d36906b8d7"), __v: 0 })   
    23. Mongoose: users.remove({ username: 'i5ting for delete' }) {}  
    24. Mongoose: users.findAndModify({ _id: ObjectId("5734490640caa6d36906b8d6") }) [] { '$set': { username: 'sang' } } { new: false, upsert: false }
    25. Mongoose: users.findAndModify({ username: 'i5ting for update 2' }) [] { '$set': { username: 'sang' } } { new: false, upsert: false }