Nodejs学习笔记（十四）— Mongoose介绍和入门
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<div class="wilson_body">
<h1 class="wilson_h1">目录</h1>
<div id="menu">
<ul>
<li>简介</li>
<li>mongoose安装</li>
<li>连接字符串</li>
<li>Schema</li>
<li>Model</li>
<li>常用数据库操作
<ul>
<li>插入</li>
<li>更新</li>
<li>删除</li>
<li>条件查询</li>
<li>数量查询</li>
<li>根据_id查询</li>
<li>模糊查询</li>
<li>分页查询</li>
</ul>
</li>
<li>其它操作</li>
<li>写在之后...</li>
</ul>
</div>
<h1 id="node_intro" class="wilson_h1">简介</h1>
<p> Mongoose是在node.js异步环境下对mongodb进行便捷操作的对象模型工具</p>
<p> 那么要使用它，首先你得装上node.js和mongodb,关于mongodb的安装和操作介绍可以参考：http://www.cnblogs.com/zhongweiv/p/node_mongodb.html</p>
<p> </p>
<p> Github地址：https://github.com/Automattic/mongoose</p>
<p> API Docs：http://mongoosejs.com/docs/guide.html</p>
<p> </p>
<p> 前面有介绍过用node-mongodb-native来操作mongodb，实际开发中估计更多会选用类似mongoose的模块来操作来提升开发效率</p>
<p> </p>
<p> 下面我们一步步来了解mongoose的基本操作^_^!</p>
<p> </p>
<h1 id="mg_install" class="wilson_h1">mongoose安装</h1>
<div class="cnblogs_code">
<pre>npm <span style="color: rgba(0, 0, 255, 1)">install</span> mongoose</pre>
</div>
<p> 安装成功后如下图：</p>
<blockquote>
<p><img src="https://images.cnblogs.com/cnblogs_com/zhongweiv/804376/o_1.png" alt="" width="810" height="341"></p>
</blockquote>
<p> 安装成功后，就可以通过 require('mongoose') 来使用！</p>
<p> </p>
<h1 id="mg_connstr" class="wilson_h1">连接字符串</h1>
<p> 创建一个db.js</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">var</span> mongoose = require('mongoose'<span style="color: rgba(0, 0, 0, 1)">),
DB_URL </span>= 'mongodb://localhost:27017/mongoosesample'<span style="color: rgba(0, 0, 0, 1)">;
</span><span style="color: rgba(0, 128, 0, 1)">/*</span><span style="color: rgba(0, 128, 0, 1)">*
* 连接
</span><span style="color: rgba(0, 128, 0, 1)">*/</span><span style="color: rgba(0, 0, 0, 1)">
mongoose.connect(DB_URL</span><span style="color: rgba(0, 0, 0, 1)">);
</span><span style="color: rgba(0, 128, 0, 1)">/*</span><span style="color: rgba(0, 128, 0, 1)">*
* 连接成功
</span><span style="color: rgba(0, 128, 0, 1)">*/</span><span style="color: rgba(0, 0, 0, 1)">
mongoose.connection.on(</span>'connected', <span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)"> () {
console.log(</span>'Mongoose connection open to ' +<span style="color: rgba(0, 0, 0, 1)"> DB_URL);
});
</span><span style="color: rgba(0, 128, 0, 1)">/*</span><span style="color: rgba(0, 128, 0, 1)">*
* 连接异常
</span><span style="color: rgba(0, 128, 0, 1)">*/</span><span style="color: rgba(0, 0, 0, 1)">
mongoose.connection.on(</span>'error',<span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)"> (err) {
console.log(</span>'Mongoose connection error: ' +<span style="color: rgba(0, 0, 0, 1)"> err);
});
</span><span style="color: rgba(0, 128, 0, 1)">/*</span><span style="color: rgba(0, 128, 0, 1)">*
* 连接断开
</span><span style="color: rgba(0, 128, 0, 1)">*/</span><span style="color: rgba(0, 0, 0, 1)">
mongoose.connection.on(</span>'disconnected', <span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)"> () {
console.log(</span>'Mongoose connection disconnected'<span style="color: rgba(0, 0, 0, 1)">);
}); </span></pre>
</div>
<p> 调用node db.js执行就会看到输出如下图</p>
<blockquote>
<p><img src="https://images.cnblogs.com/cnblogs_com/zhongweiv/804376/o_3.png" alt="" width="810" height="120"></p>
</blockquote>
<p> 从代码中可以看出，监听了几个事件，并且执行触发了connected事件，这表示连接成功</p>
<p> connection中不止有如上几个事件，关键看你想要监听哪个事件。</p>
<p> </p>
<p> 其它事件可以自行查看：http://mongoosejs.com/docs/api.html#connection_Connection</p>
<p> </p>
<p> 这是最简单的连接字符串，当然还有其它形式，比如：连接密码、数据库连接设置、集群方式连式等等，这里解释了，用着了时候自行查询API文档</p>
<p> http://mongoosejs.com/docs/api.html#index-js</p>
<p> </p>
<h1 id="mg_schema" class="wilson_h1">Schema</h1>
<p> schema是mongoose里会用到的一种数据模式，可以理解为表结构的定义；每个schema会映射到mongodb中的一个collection，它不具备操作数据库的能力</p>
<p> 我们先改造一下db.js，导出mongoose对象 </p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">var</span> mongoose = require('mongoose'<span style="color: rgba(0, 0, 0, 1)">),
DB_URL </span>= 'mongodb://localhost:27017/mongoosesample'<span style="color: rgba(0, 0, 0, 1)">;
</span><span style="color: rgba(0, 128, 0, 1)">/*</span><span style="color: rgba(0, 128, 0, 1)">*
* 连接
</span><span style="color: rgba(0, 128, 0, 1)">*/</span><span style="color: rgba(0, 0, 0, 1)">
mongoose.connect(DB_URL);
</span><span style="color: rgba(0, 128, 0, 1)">/*</span><span style="color: rgba(0, 128, 0, 1)">*
* 连接成功
</span><span style="color: rgba(0, 128, 0, 1)">*/</span><span style="color: rgba(0, 0, 0, 1)">
mongoose.connection.on(</span>'connected', <span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)"> () {
console.log(</span>'Mongoose connection open to ' +<span style="color: rgba(0, 0, 0, 1)"> DB_URL);
});
</span><span style="color: rgba(0, 128, 0, 1)">/*</span><span style="color: rgba(0, 128, 0, 1)">*
* 连接异常
</span><span style="color: rgba(0, 128, 0, 1)">*/</span><span style="color: rgba(0, 0, 0, 1)">
mongoose.connection.on(</span>'error',<span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)"> (err) {
console.log(</span>'Mongoose connection error: ' +<span style="color: rgba(0, 0, 0, 1)"> err);
});
</span><span style="color: rgba(0, 128, 0, 1)">/*</span><span style="color: rgba(0, 128, 0, 1)">*
* 连接断开
</span><span style="color: rgba(0, 128, 0, 1)">*/</span><span style="color: rgba(0, 0, 0, 1)">
mongoose.connection.on(</span>'disconnected', <span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)"> () {
console.log(</span>'Mongoose connection disconnected'<span style="color: rgba(0, 0, 0, 1)">);
});
<span style="color: rgba(255, 0, 0, 1)">module.exports </span></span><span style="color: rgba(255, 0, 0, 1)">= mongoose;</span></pre>
</div>
<p> 下面我们定义一个user的Schema，命名为user.js</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 128, 0, 1)">/*</span><span style="color: rgba(0, 128, 0, 1)">*
* 用户信息
</span><span style="color: rgba(0, 128, 0, 1)">*/</span>
<span style="color: rgba(0, 0, 255, 1)">var</span> mongoose = require('./db.js'<span style="color: rgba(0, 0, 0, 1)">),
Schema </span>=<span style="color: rgba(0, 0, 0, 1)"> mongoose.Schema;
</span><span style="color: rgba(0, 0, 255, 1)">var</span> UserSchema = <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> Schema({
username : { type: String }, </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">用户账号</span>
userpwd: {type: String}, <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">密码</span>
userage: {type: Number}, <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">年龄</span>
logindate : { type: Date} <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">最近登录时间</span>
<span style="color: rgba(0, 0, 0, 1)">});<br></span></pre>
</div>
<p> 定义一个Schema就这么简单，指定字段名和类型</p>
<p> Schema Types内置类型如下：</p>
<p><span style="background-color: rgba(255, 255, 255, 1); color: rgba(0, 0, 0, 1)"><em> String</em></span></p>
<p><span style="background-color: rgba(255, 255, 255, 1); color: rgba(0, 0, 0, 1)"><em> Number</em></span></p>
<p><span style="background-color: rgba(255, 255, 255, 1); color: rgba(0, 0, 0, 1)"><em> Boolean | Bool</em></span></p>
<p><span style="background-color: rgba(255, 255, 255, 1); color: rgba(0, 0, 0, 1)"><em> Array</em></span></p>
<p><span style="background-color: rgba(255, 255, 255, 1); color: rgba(0, 0, 0, 1)"><em> Buffer</em></span></p>
<p><span style="background-color: rgba(255, 255, 255, 1); color: rgba(0, 0, 0, 1)"><em> Date</em></span></p>
<p><span style="background-color: rgba(255, 255, 255, 1); color: rgba(0, 0, 0, 1)"><em> ObjectId | Oid</em></span></p>
<p><span style="background-color: rgba(255, 255, 255, 1); color: rgba(0, 0, 0, 1)"><em> Mixed</em></span></p>
<p> </p>
<p><span class="wilson_tip"> Schema中还可以做一些常用事，后面再讲！</span></p>
<p> </p>
<h1 id="mg_model" class="wilson_h1">Model</h1>
<p> 定义好了Schema，接下就是生成Model。</p>
<p> model是由schema生成的模型，可以对数据库的操作</p>
<p> 我们对上面的定义的user的schema生成一个User的model并导出，修改后代码如下</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 128, 0, 1)">/*</span><span style="color: rgba(0, 128, 0, 1)">*
* 用户信息
</span><span style="color: rgba(0, 128, 0, 1)">*/</span>
<span style="color: rgba(0, 0, 255, 1)">var</span> mongoose = require('./db.js'<span style="color: rgba(0, 0, 0, 1)">),
Schema </span>=<span style="color: rgba(0, 0, 0, 1)"> mongoose.Schema;
</span><span style="color: rgba(0, 0, 255, 1)">var</span> UserSchema = <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> Schema({
username : { type: String }, </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">用户账号</span>
userpwd: {type: String}, <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">密码</span>
userage: {type: Number}, <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">年龄</span>
logindate : { type: Date} <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">最近登录时间</span>
<span style="color: rgba(0, 0, 0, 1)">});
<span style="color: rgba(255, 0, 0, 1)">module.exports </span></span><span style="color: rgba(255, 0, 0, 1)">= mongoose.model('User',UserSchema);</span></pre>
</div>
<p> </p>
<h1 id="mg_op" class="wilson_h1">常用数据库操作</h1>
<p> 接下来创建一个test.js文件做一些常用操作演示。</p>
<p><strong> 插入</strong></p>
<p><strong> </strong><em><span style="color: rgba(0, 204, 255, 1)">Model#save()</span></em></p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">var</span> User = require("./user.js"<span style="color: rgba(0, 0, 0, 1)">);
</span><span style="color: rgba(0, 128, 0, 1)">/*</span><span style="color: rgba(0, 128, 0, 1)">*
* 插入
</span><span style="color: rgba(0, 128, 0, 1)">*/</span>
<span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)"> insert() {
</span><span style="color: rgba(0, 0, 255, 1)">var</span> user = <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> User({
username : </span>'Tracy McGrady', <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">用户账号</span>
userpwd: 'abcd', <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">密码</span>
userage: 37, <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">年龄</span>
logindate : <span style="color: rgba(0, 0, 255, 1)">new</span> Date() <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">最近登录时间</span>
<span style="color: rgba(0, 0, 0, 1)"> });
user.<span style="color: rgba(255, 0, 0, 1)">save</span>(</span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)"> (err, res) {
</span><span style="color: rgba(0, 0, 255, 1)">if</span><span style="color: rgba(0, 0, 0, 1)"> (err) {
console.log(</span>"Error:" +<span style="color: rgba(0, 0, 0, 1)"> err);
}
</span><span style="color: rgba(0, 0, 255, 1)">else</span><span style="color: rgba(0, 0, 0, 1)"> {
console.log(</span>"Res:" +<span style="color: rgba(0, 0, 0, 1)"> res);
}
});
}
insert();</span></pre>
</div>
<p> 结果在robmongo工具中查看</p>
<blockquote>
<p><img src="https://images.cnblogs.com/cnblogs_com/zhongweiv/804376/o_5.png" alt="" width="785" height="275"></p>
</blockquote>
<p> 从图中可以看到插入成功！ </p>
<p> </p>
<p> <strong>更新</strong> </p>
<p><span style="color: rgba(0, 204, 255, 1)"><em> Model.update(conditions, update, , )</em></span></p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">var</span> User = require("./user.js"<span style="color: rgba(0, 0, 0, 1)">);
</span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)"> update(){
</span><span style="color: rgba(0, 0, 255, 1)">var</span> wherestr = {'username' : 'Tracy McGrady'<span style="color: rgba(0, 0, 0, 1)">};
</span><span style="color: rgba(0, 0, 255, 1)">var</span> updatestr = {'userpwd': 'zzzz'<span style="color: rgba(0, 0, 0, 1)">};
User.<span style="color: rgba(255, 0, 0, 1)">update</span>(wherestr, updatestr, </span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)">(err, res){
</span><span style="color: rgba(0, 0, 255, 1)">if</span><span style="color: rgba(0, 0, 0, 1)"> (err) {
console.log(</span>"Error:" +<span style="color: rgba(0, 0, 0, 1)"> err);
}
</span><span style="color: rgba(0, 0, 255, 1)">else</span><span style="color: rgba(0, 0, 0, 1)"> {
console.log(</span>"Res:" +<span style="color: rgba(0, 0, 0, 1)"> res);
}
})
}
update();</span></pre>
</div>
<p> 根据用户名更新密码，执行后结果如图</p>
<blockquote>
<p><img src="https://images.cnblogs.com/cnblogs_com/zhongweiv/804376/o_7.png" alt="" width="785" height="275"></p>
</blockquote>
<p> 图中可以看出，密码更新成功！<span style="color: rgba(255, 0, 0, 1)"><span style="color: rgba(0, 0, 0, 1)">update</span></span>方法基本可以满足所有更新！</p>
<p> </p>
<p> 常用方法还有findByIdAndUpdate，这种比较有指定性，就是根据_id</p>
<p><em><span style="color: rgba(0, 204, 255, 1)"> Model.findByIdAndUpdate(id, , , )</span></em></p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">var</span> User = require("./user.js"<span style="color: rgba(0, 0, 0, 1)">);
</span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)"> findByIdAndUpdate</span><span style="color: rgba(0, 0, 0, 1)">(){
</span><span style="color: rgba(0, 0, 255, 1)">var</span> id = '56f2558b2dd74855a345edb2'<span style="color: rgba(0, 0, 0, 1)">;
</span><span style="color: rgba(0, 0, 255, 1)">var</span> updatestr = {'userpwd': 'abcd'<span style="color: rgba(0, 0, 0, 1)">};
User.<span style="color: rgba(255, 0, 0, 1)">findByIdAndUpdate</span>(id, updatestr, </span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)">(err, res){
</span><span style="color: rgba(0, 0, 255, 1)">if</span><span style="color: rgba(0, 0, 0, 1)"> (err) {
console.log(</span>"Error:" +<span style="color: rgba(0, 0, 0, 1)"> err);
}
</span><span style="color: rgba(0, 0, 255, 1)">else</span><span style="color: rgba(0, 0, 0, 1)"> {
console.log(</span>"Res:" +<span style="color: rgba(0, 0, 0, 1)"> res);
}
})
}
findByIdAndUpdate();</span></pre>
</div>
<p> </p>
<p> 其它更新方法</p>
<p> <em><span style="color: rgba(0, 204, 255, 1)">Model.findOneAndUpdate(, , , )</span></em> //找到一条记录并更新</p>
<p> </p>
<p> <strong>删除</strong></p>
<p> <em><span style="color: rgba(0, 204, 255, 1)">Model.remove(conditions, )</span></em></p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">var</span> User = require("./user.js"<span style="color: rgba(0, 0, 0, 1)">);
</span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)"> del(){
</span><span style="color: rgba(0, 0, 255, 1)">var</span> wherestr = {'username' : 'Tracy McGrady'<span style="color: rgba(0, 0, 0, 1)">};
User.<span style="color: rgba(255, 0, 0, 1)">remove</span>(wherestr, </span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)">(err, res){
</span><span style="color: rgba(0, 0, 255, 1)">if</span><span style="color: rgba(0, 0, 0, 1)"> (err) {
console.log(</span>"Error:" +<span style="color: rgba(0, 0, 0, 1)"> err);
}
</span><span style="color: rgba(0, 0, 255, 1)">else</span><span style="color: rgba(0, 0, 0, 1)"> {
console.log(</span>"Res:" +<span style="color: rgba(0, 0, 0, 1)"> res);
}
})
}
del();</span></pre>
</div>
<p> 结果就不贴了，res中会返回是否成功以及影响的行数：<em>{"ok":1,"n":1}</em></p>
<p> </p>
<p> 其它常用方法还有： </p>
<p> <em><span style="color: rgba(0, 204, 255, 1)">Model.findByIdAndRemove(id, , ) </span></em></p>
<p><span style="color: rgba(0, 204, 255, 1)"><em> Model.findOneAndRemove(conditions, , )</em></span></p>
<p> </p>
<p> <strong>条件查询</strong></p>
<p> 已先插入一些测试数据 。。</p>
<p><span style="color: rgba(0, 204, 255, 1)"><em> Model.find(conditions, , , )</em></span></p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">var</span> User = require("./user.js"<span style="color: rgba(0, 0, 0, 1)">);
</span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)"> getByConditions(){
</span><span style="color: rgba(0, 0, 255, 1)">var</span> wherestr = {'username' : 'Tracy McGrady'<span style="color: rgba(0, 0, 0, 1)">};
User.<span style="color: rgba(255, 0, 0, 1)">find</span>(wherestr, </span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)">(err, res){
</span><span style="color: rgba(0, 0, 255, 1)">if</span><span style="color: rgba(0, 0, 0, 1)"> (err) {
console.log(</span>"Error:" +<span style="color: rgba(0, 0, 0, 1)"> err);
}
</span><span style="color: rgba(0, 0, 255, 1)">else</span><span style="color: rgba(0, 0, 0, 1)"> {
console.log(</span>"Res:" +<span style="color: rgba(0, 0, 0, 1)"> res);
}
})
}
getByConditions();</span></pre>
</div>
<p> 结果我就不展示了</p>
<p> 第2个参数可以设置要查询输出的字段,比如改成</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">var</span> User = require("./user.js"<span style="color: rgba(0, 0, 0, 1)">);
</span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)"> getByConditions(){
</span><span style="color: rgba(0, 0, 255, 1)">var</span> wherestr = {'username' : 'Tracy McGrady'<span style="color: rgba(0, 0, 0, 1)">};
</span><span style="color: rgba(255, 0, 0, 1)">var opt = {"username": 1 ,"_id": 0</span><span style="color: rgba(0, 0, 0, 1)"><span style="color: rgba(255, 0, 0, 1)">};</span>
User.find(wherestr, opt, </span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)">(err, res){
</span><span style="color: rgba(0, 0, 255, 1)">if</span><span style="color: rgba(0, 0, 0, 1)"> (err) {
console.log(</span>"Error:" +<span style="color: rgba(0, 0, 0, 1)"> err);
}
</span><span style="color: rgba(0, 0, 255, 1)">else</span><span style="color: rgba(0, 0, 0, 1)"> {
console.log(</span>"Res:" +<span style="color: rgba(0, 0, 0, 1)"> res);
}
})
}
getByConditions();</span></pre>
</div>
<p> 输出只会有username字段，设置方法如上，1表示查询输出该字段，0表示不输出</p>
<p> </p>
<p> 比如我要查询年龄范围条件应该怎么写呢？</p>
<p><span style="color: rgba(0, 204, 255, 1)"><em> User.find({userage: {$gte: 21, $lte: 65}}, callback); </em></span><span style="color: rgba(0, 204, 255, 1)"><span style="color: rgba(0, 0, 0, 1)">//这表示查询年龄大于等21而且小于等于65岁</span></span></p>
<p> </p>
<p><span style="color: rgba(0, 204, 255, 1)"><span style="color: rgba(0, 0, 0, 1)"> 其实类似的还有：</span></span><span style="color: rgba(0, 204, 255, 1)"><span style="color: rgba(0, 0, 0, 1)"> </span></span></p>
<p> $or 或关系</p>
<p> $nor 或关系取反</p>
<p> $gt 大于</p>
<p> $gte 大于等于</p>
<p> $lt 小于</p>
<p> $lte 小于等于</p>
<p> $ne 不等于</p>
<p> $in 在多个值范围内</p>
<p> $nin 不在多个值范围内</p>
<p> $all 匹配数组中多个值</p>
<p> $regex 正则，用于模糊查询</p>
<p> $size 匹配数组大小</p>
<p> $maxDistance 范围查询，距离（基于LBS）</p>
<p> $mod 取模运算</p>
<p> $near 邻域查询，查询附近的位置（基于LBS）</p>
<p> $exists 字段是否存在</p>
<p> $elemMatch 匹配内数组内的元素</p>
<p> $within 范围查询（基于LBS）</p>
<p> $box 范围查询，矩形范围（基于LBS）</p>
<p> $center 范围醒询，圆形范围（基于LBS）</p>
<p> $centerSphere 范围查询，球形范围（基于LBS）</p>
<p> $slice 查询字段集合中的元素（比如从第几个之后，第N到第M个元素）</p>
<p> </p>
<p> 可能还有一些，没什么印象，大家自行看看api ^_^! </p>
<p> </p>
<p> <strong>数量查询</strong></p>
<p><em><span style="color: rgba(0, 204, 255, 1)"> Model.count(conditions, )</span></em></p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">var</span> User = require("./user.js"<span style="color: rgba(0, 0, 0, 1)">);
</span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)"> getCountByConditions(){
</span><span style="color: rgba(0, 0, 255, 1)">var</span> wherestr =<span style="color: rgba(0, 0, 0, 1)"> {};
User.<span style="color: rgba(255, 0, 0, 1)">count</span>(wherestr, </span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)">(err, res){
</span><span style="color: rgba(0, 0, 255, 1)">if</span><span style="color: rgba(0, 0, 0, 1)"> (err) {
console.log(</span>"Error:" +<span style="color: rgba(0, 0, 0, 1)"> err);
}
</span><span style="color: rgba(0, 0, 255, 1)">else</span><span style="color: rgba(0, 0, 0, 1)"> {
console.log(</span>"Res:" +<span style="color: rgba(0, 0, 0, 1)"> res);
}
})
}</span></pre>
<pre><span>getCountByConditions();</span></pre>
</div>
<p> res会输出数量，也可以传入条件做条件查询！</p>
<p> <strong>根据_id查询</strong></p>
<p><em><span style="color: rgba(0, 204, 255, 1)"> Model.findById(id, , , )</span></em></p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">var</span> User = require("./user.js"<span style="color: rgba(0, 0, 0, 1)">);
</span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)"> getById(){
</span><span style="color: rgba(0, 0, 255, 1)">var</span> id = '56f261fb448779caa359cb73'<span style="color: rgba(0, 0, 0, 1)">;
User.<span style="color: rgba(255, 0, 0, 1)">findById</span>(id, </span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)">(err, res){
</span><span style="color: rgba(0, 0, 255, 1)">if</span><span style="color: rgba(0, 0, 0, 1)"> (err) {
console.log(</span>"Error:" +<span style="color: rgba(0, 0, 0, 1)"> err);
}
</span><span style="color: rgba(0, 0, 255, 1)">else</span><span style="color: rgba(0, 0, 0, 1)"> {
console.log(</span>"Res:" +<span style="color: rgba(0, 0, 0, 1)"> res);
}
})
}
getById();</span></pre>
</div>
<p> 这个还是比较常用，要据ID得到数据！ </p>
<p> <strong>模糊查询</strong></p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">var</span> User = require("./user.js"<span style="color: rgba(0, 0, 0, 1)">);
</span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)"> getByRegex(){
</span><span style="color: rgba(0, 0, 255, 1)">var</span> whereStr = {'username':{<span style="color: rgba(255, 0, 0, 1)">$regex</span>:/m/<span style="color: rgba(0, 0, 0, 1)">i}};
User.find(whereStr, </span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)">(err, res){
</span><span style="color: rgba(0, 0, 255, 1)">if</span><span style="color: rgba(0, 0, 0, 1)"> (err) {
console.log(</span>"Error:" +<span style="color: rgba(0, 0, 0, 1)"> err);
}
</span><span style="color: rgba(0, 0, 255, 1)">else</span><span style="color: rgba(0, 0, 0, 1)"> {
console.log(</span>"Res:" +<span style="color: rgba(0, 0, 0, 1)"> res);
}
})
}
getByRegex();</span></pre>
</div>
<p> 上面示例中查询出所有用户名中有'm'的名字，且不区分大小写，模糊查询比较常用，正则形式匹配，正则方式就是javascript正则，用到的比较多！</p>
<p> <strong>分页查询</strong></p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">var</span> User = require("./user.js"<span style="color: rgba(0, 0, 0, 1)">);
</span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)"> getByPager(){
</span><span style="color: rgba(0, 0, 255, 1)">var</span> pageSize = 5; <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">一页多少条</span>
<span style="color: rgba(0, 0, 255, 1)">var</span> currentPage = 1; <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">当前第几页</span>
<span style="color: rgba(0, 0, 255, 1)">var</span> sort = {'logindate':-1}; <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">排序（按登录时间倒序）</span>
<span style="color: rgba(0, 0, 255, 1)">var</span> condition = {}; <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">条件</span>
<span style="color: rgba(0, 0, 255, 1)">var</span> skipnum = (currentPage - 1) * pageSize; <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">跳过数</span>
<span style="color: rgba(0, 0, 0, 1)">
User.find(condition).skip(skipnum).limit(pageSize).sort(sort).exec(</span><span style="color: rgba(0, 0, 255, 1)">function</span><span style="color: rgba(0, 0, 0, 1)"> (err, res) {
</span><span style="color: rgba(0, 0, 255, 1)">if</span><span style="color: rgba(0, 0, 0, 1)"> (err) {
console.log(</span>"Error:" +<span style="color: rgba(0, 0, 0, 1)"> err);
}
</span><span style="color: rgba(0, 0, 255, 1)">else</span><span style="color: rgba(0, 0, 0, 1)"> {
console.log(</span>"Res:" +<span style="color: rgba(0, 0, 0, 1)"> res);
}
})
}
getByPager();</span></pre>
</div>
<p> 分页是用得比较多的查询，分页原理用过其它数据库的都知道，分页用到的函数和mysql的比较类似</p>
<p> 上面我用到<span style="color: rgba(255, 0, 0, 1)">sort(),<span style="color: rgba(0, 0, 0, 1)">这个是排序规则，就不单讲了！</span></span></p>
<h1 id="node_others" class="wilson_h1">其它操作</h1>
<p> 其它还有比较多常用的</p>
<p> <strong>索引和默认值</strong></p>
<p> 再看看我对user.js这个schema的修改</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 128, 0, 1)">/*</span><span style="color: rgba(0, 128, 0, 1)">*
* 用户信息
</span><span style="color: rgba(0, 128, 0, 1)">*/</span>
<span style="color: rgba(0, 0, 255, 1)">var</span> mongoose = require('./db.js'<span style="color: rgba(0, 0, 0, 1)">),
Schema </span>=<span style="color: rgba(0, 0, 0, 1)"> mongoose.Schema;
</span><span style="color: rgba(0, 0, 255, 1)">var</span> UserSchema = <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> Schema({
username : { type: String , <span style="color: rgba(255, 0, 0, 1)">index: </span></span><span style="color: rgba(255, 0, 0, 1)">true</span>}, <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">用户账号</span>
userpwd: {type: String}, <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">密码</span>
userage: {type: Number}, <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">年龄</span>
logindate : { type: Date, <span style="color: rgba(255, 0, 0, 1)">default:Date.now</span>} <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">最近登录时间</span>
<span style="color: rgba(0, 0, 0, 1)">});
module.exports </span>= mongoose.model('User',UserSchema);</pre>
</div>
<p> index ：建索引</p>
<p> default：默认值</p>
<p> </p>
<p> <strong>LBS地址位置</strong></p>
<div class="cnblogs_code">
<pre>lbs : { type: Array, index: '2d', sparse: <span style="color: rgba(0, 0, 255, 1)">true</span> } <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">地理位置</span></pre>
</div>
<p> 上面有介绍过很多基于LBS的条件查询，Schema中定义时如上</p>
<p> LBS查询对于一些基于LBS应用会用得比较多。</p>
<p> </p>
<p> <strong>其它常用方法</strong></p>
<p><span style="color: rgba(0, 204, 255, 1)"><em> Model.distinct(field, , ) </em></span> //去重</p>
<p><span style="color: rgba(0, 204, 255, 1)"><em> Model.findOne(conditions, , , ) </em></span> //查找一条记录</p>
<p><em><span style="color: rgba(0, 204, 255, 1)"> Model.findOneAndRemove(conditions, , ) </span></em> //查找一条记录并删除</p>
<p><em><span style="color: rgba(0, 204, 255, 1)"> Model.findOneAndUpdate(, , , )</span> </em> //查找一条记录并更新</p>
<p> </p>
<h1 id="node_aferwords" class="wilson_h1">写在之后...</h1>
<p> mongoose操作基本入门大致就是这些，自已试一下，入门完全没问题，并且比node-mongodb-native还是要简单明了一些，</p>
<p> 在node.js中操作数据库，如果逻辑相对复杂时，大量的回调嵌套还是比较郁闷的，下一篇于mongoose操作多逻辑组合回调嵌套的问题给出一种方案^_^!</p>
<p> </p>
</div>
</div>
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作 者：
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