MongoDB （ 四 ）高级_find修饰符

头像
Meils
    阅读 10 分钟
    1

    find查询操作是我们平时再开发中最常用的，也是重中之重。

    find基本操作符
    // 批量插入数据

var workmate1={
  name:'JSPang',
  age:33,
  sex:1,
  job:'前端',
  skill:{
      skillOne:'HTML+CSS',
      skillTwo:'JavaScript',
      skillThree:'PHP'
  },
  regeditTime:new Date(),
  interest:[]
}
var workmate2={
  name:'ShengLei',
  age:31,
  sex:1,
  job:'JAVA后端',
  skill:{
      skillOne:'HTML+CSS',
      skillTwo:'J2EE',
      skillThree:'PPT'
  },
  regeditTime:new Date(),
  interest:[]
}
var workmate3={
  name:'MinJie',
  age:18,
  sex:0,
  job:'UI',
  skill:{
      skillOne:'PhotoShop',
      skillTwo:'UI',
      skillThree:'PPT'
  },
  regeditTime:new Date(),
  interest:[]
}
var workmate4={
  name:'XiaoWang',
  age:25,
  sex:1,
  job:'UI',
  skill:{
      skillOne:'PhotoShop',
      skillTwo:'UI',
      skillThree:'PPT'
  },
  regeditTime:new Date(),
  interest:[]
}
var workmate5={
  name:'LiangPeng',
  age:28,
  sex:1,
  job:'前端',
  skill:{
      skillOne:'HTML+CSS',
      skillTwo:'JavaScript',
  },
  regeditTime:new Date(),
  interest:[]
}
var workmate6={
  name:'HouFei',
  age:25,
  sex:0,
  job:'前端',
  skill:{
      skillOne:'HTML+CSS',
      skillTwo:'JavaScript',
  },
  regeditTime:new Date(),
  interest:[]
}
var workmate7={
  name:'LiuYan',
  age:35,
  sex:0,
  job:'美工',
  skill:{
      skillOne:'PhotoShop',
      skillTwo:'CAD',
  },
  regeditTime:new Date(),
  interest:[]
}
var workmate8={
  name:'DingLu',
  age:20,
  sex:0,
  job:'美工',
  skill:{
      skillOne:'PhotoShop',
      skillTwo:'CAD',
  },
  regeditTime:new Date(),
  interest:[]
}
var workmate9={
  name:'JiaPeng',
  age:29,
  sex:1,
  job:'前端',
  skill:{
      skillOne:'HTML+CSS',
      skillTwo:'JavaScript',
      skillThree:'PHP'
  },
  regeditTime:new Date(),
  interest:[]
}
var workmate10={
  name:'LiJia',
  age:26,
  sex:0,
  job:'前端',
  skill:{
      skillOne:'HTML+CSS',
      skillTwo:'JavaScript',
      skillThree:'PHP'
  },
  regeditTime:new Date(),
  interest:[]
}
var db=connect('company');
var workmateArray=[workmate1,workmate2,workmate3,workmate4,workmate5,workmate6,workmate7,workmate8,workmate9,workmate10];
db.workmate.insert(workmateArray);
print('[SUCCESS]：The data was inserted successfully');
    // 启动数据库
PS D:\myweb\node\mongodb\01> mongo   // 启动mongo
MongoDB shell version v3.4.10
connecting to: mongodb://127.0.0.1:27017
MongoDB server version: 3.4.10
Server has startup warnings:
2018-04-01T17:32:00.547+0800 I CONTROL  [initandlisten]
2018-04-01T17:32:00.548+0800 I CONTROL  [initandlisten] ** WARNIN
G: Access control is not enabled for the database.
2018-04-01T17:32:00.548+0800 I CONTROL  [initandlisten] **
   Read and write access to data and configuration is unrestricte          
d.
2018-04-01T17:32:00.548+0800 I CONTROL  [initandlisten]
> load('./demo.js')                    // 加载js文件批量插入
connecting to: mongodb://127.0.0.1:27017/company
MongoDB server version: 3.4.10
[SUCCESS]：The data was inserted successfully
true
>
    // 我们需要查找技能一中会HTML 和 CSS 的所有人
db.workmate.find({"skill.skillOne": "HTML+CSS"});

    筛选字段

    // 如我们只需要姓名和技能
db.workmate.find({"skill.skillOne": "HTML+CSS"}, { name: true, "skill.skillOne": true});

// find()的第二个参数用于指定要返回的字段
> db.workmate.find({"skill.skillOne": "HTML+CSS"}, { name: true, "skill.skillOne": true});
{ "_id" : ObjectId("5ac0ba2d945d6de2ecdcd0ec"), "name" : "JSPang", "skill" : { "skillOne" : "HTML+CSS" } }
{ "_id" : ObjectId("5ac0ba2d945d6de2ecdcd0ed"), "name" : "ShengLei", "skill" : { "skillOne" : "HTML+CSS" } }
{ "_id" : ObjectId("5ac0ba2d945d6de2ecdcd0f0"), "name" : "LiangPeng", "skill" : { "skillOne" : "HTML+CSS" } }
{ "_id" : ObjectId("5ac0ba2d945d6de2ecdcd0f1"), "name" : "HouFei", "skill" : { "skillOne" : "HTML+CSS" } }
{ "_id" : ObjectId("5ac0ba2d945d6de2ecdcd0f4"), "name" : "JiaPeng", "skill" : { "skillOne" : "HTML+CSS" } }
{ "_id" : ObjectId("5ac0ba2d945d6de2ecdcd0f5"), "name" : "LiJia", "skill" : { "skillOne" : "HTML+CSS" } }
>

// 如果我们不想要_id
db.workmate.find(
    {"skill.skillOne":"HTML+CSS"},
    { name:true, "skill.skillOne":true, _id:false }
);

    其他查询修饰符

    • 不等修饰符
    1. 小于($lt):英文全称less-than
    2. 小于等于($lte)：英文全称less-than-equal
    3. 大于($gt):英文全称greater-than
    4. 大于等于($gte):英文全称greater-than-equal
    5. 不等于($ne):英文全称not-equal
    db.workmate.find(
    {age:{$lte:30,$gte:25}},
    {name:true,age:true,"skill.skillOne":true,_id:false}
)

    日期查找

    var startDate= new Date('01/01/2018');
db.workmate.find(
    {regeditTime:{$gt:startDate}},
    {name:true,age:true,"skill.skillOne":true,_id:false}
)
    find多条件查询

    $in

    db.workmate.find({age:{$in:[25,33]}},
    {name:1,"skill.skillOne":1,age:1,_id:0}
)
// 查询年龄是 25 和 33 的

    $or

    db.workmate.find({$or:[
    {age:{$gte:30}},
    {"skill.skillThree":'PHP'}
]},
    {name:1,"skill.skillThree":1,age:1,_id:0}
)

    $and

    db.workmate.find({$and:[
    {age:{$gte:30}},
    {"skill.skillThree":'PHP'}
]},
    {name:1,"skill.skillThree":1,age:1,_id:0}
)

    $not

    db.workmate.find({
    age:{
        $not:{
            $lte:30,
            $gte:20
        }
    }
},
{name:1,"skill.skillOne":1,age:1,_id:0}
)
    • 更多请查看下面的文档

    Mongodb 重温之路（二）

    find 数组查询
    // 数据中增加了一个数组
var workmate1={
    name:'JSPang',
    age:33,
    sex:1,
    job:'前端',
    skill:{
        skillOne:'HTML+CSS',
        skillTwo:'JavaScript',
        skillThree:'PHP'
    },
    regeditTime:new Date(),
    interest:['看电影','看书','吃美食','钓鱼','旅游']
}
 
var workmate2={
    name:'ShengLei',
    age:31,
    sex:1,
    job:'JAVA后端',
    skill:{
        skillOne:'HTML+CSS',
        skillTwo:'J2EE',
        skillThree:'PPT'
    },
    regeditTime:new Date(),
    interest:['篮球','看电影','做饭']
}
 
var workmate3={
    name:'MinJie',
    age:18,
    sex:0,
    job:'UI',
    skill:{
        skillOne:'PhotoShop',
        skillTwo:'UI',
        skillThree:'PPT'
    },
    regeditTime:new Date(),
    interest:['做饭','画画','看电影']
}
var workmate4={
    name:'XiaoWang',
    age:25,
    sex:1,
    job:'UI',
    skill:{
        skillOne:'PhotoShop',
        skillTwo:'UI',
        skillThree:'PPT'
    },
    regeditTime:new Date(),
    interest:['写代码','篮球','画画']
}
var workmate5={
    name:'LiangPeng',
    age:28,
    sex:1,
    job:'前端',
    skill:{
        skillOne:'HTML+CSS',
        skillTwo:'JavaScript',
    },
    regeditTime:new Date(),
    interest:['玩游戏','写代码','做饭']
}
 
var workmate6={
    name:'HouFei',
    age:25,
    sex:0,
    job:'前端',
    skill:{
        skillOne:'HTML+CSS',
        skillTwo:'JavaScript',
    },
    regeditTime:new Date(),
    interest:['化妆','读书','做饭']
}
 
var workmate7={
    name:'LiuYan',
    age:35,
    sex:0,
    job:'美工',
    skill:{
        skillOne:'PhotoShop',
        skillTwo:'CAD',
    },
    regeditTime:new Date(),
    interest:['画画','聚会','看电影']
}
 
 
var workmate8={
    name:'DingLu',
    age:20,
    sex:0,
    job:'美工',
    skill:{
        skillOne:'PhotoShop',
        skillTwo:'CAD',
    },
    regeditTime:new Date(),
    interest:['美食','看电影','做饭']
}
 
var workmate9={
    name:'JiaPeng',
    age:29,
    sex:1,
    job:'前端',
    skill:{
        skillOne:'HTML+CSS',
        skillTwo:'JavaScript',
        skillThree:'PHP'
    },
    regeditTime:new Date(),
    interest:['写代码','篮球','游泳']
}
 
var workmate10={
    name:'LiJia',
    age:26,
    sex:0,
    job:'前端',
    skill:{
        skillOne:'HTML+CSS',
        skillTwo:'JavaScript',
        skillThree:'PHP'
    },
    regeditTime:new Date(),
    interest:['玩游戏','美食','篮球']
}
 
 
 
var db=connect('company');
var workmateArray=[workmate1,workmate2,workmate3,workmate4,workmate5,workmate6,workmate7,workmate8,workmate9,workmate10];
db.workmate.insert(workmateArray);
print('[SUCCESS]：The data was inserted successfully');

    基本数组查询

    // 比如现在我们知道了一个人的爱好是'画画','聚会','看电影'，但我们不知道是谁，这时候我们就可以使用最简单的数组查询

> db.workmate.find({interest: ['画画','聚会','看电影']}, {
...     name: true, interest: true, age: true, _id: 0
... });

{ "name" : "LiuYan", "age" : 35, "interest" : [ "画画", "聚会", "看电影" ] }
    // 想看兴趣中含有看电影的员工
> db.workmate.find({interest: '看电影'}, {name: 1, _id: 0, interest: 1})
{ "name" : "JSPang", "interest" : [ "看电影", "看书", "吃美食", "钓鱼", "旅游" ] }
{ "name" : "ShengLei", "interest" : [ "篮球", "看电影", "做饭" ] }
{ "name" : "MinJie", "interest" : [ "做饭", "画画", "看电影" ] }
{ "name" : "LiuYan", "interest" : [ "画画", "聚会", "看电影" ] }
{ "name" : "DingLu", "interest" : [ "美食", "看电影", "做饭" ] }

    $all-数组多项查询

    // 要查询出喜欢看电影和看书的人员信息，

>  db.workmate.find(
...    {interest: {$all : ['看电影', '看书']}},
...    {name: 1, age: 1, _id: 0, interest: true}
... );
{ "name" : "JSPang", "age" : 33, "interest" : [ "看电影", "看书", "吃美食", "钓鱼", "旅游" ] }
>

    数组的$in或者查询

    // 看电影和看书有一样就行了
> db.workmate.find(
...     {interest:{$in:["看电影","看书"]}},
...     {name:1,interest:1,age:1,_id:0}
... )
{ "name" : "JSPang", "age" : 33, "interest" : [ "看电影", "看书", "吃美食", "钓鱼", "旅游" ] }
{ "name" : "ShengLei", "age" : 31, "interest" : [ "篮球", "看电影", "做饭" ] }
{ "name" : "MinJie", "age" : 18, "interest" : [ "做饭", "画画", "看电影" ] }
{ "name" : "LiuYan", "age" : 35, "interest" : [ "画画", "聚会", "看电影" ] }
{ "name" : "DingLu", "age" : 20, "interest" : [ "美食", "看电影", "做饭" ] }
>

    $size-数组个数查询

    // 查询数组长度
db.workmate.find(
    {interest:{$size:5}},
    {name:1,interest:1,age:1,_id:0} 
)

    $slice-显示选项

    // 比如我们现在想显示每个人兴趣的前两项，而不是把每个人所有的兴趣都显示出来。

> db.workmate.find(
...     {},
...     {name:1,interest:{$slice:2},age:1,_id:0}
... )
{ "name" : "JSPang", "age" : 33, "interest" : [ "看电影", "看书" ] }
{ "name" : "ShengLei", "age" : 31, "interest" : [ "篮球", "看电影" ] }
{ "name" : "MinJie", "age" : 18, "interest" : [ "做饭", "画画" ] }
{ "name" : "XiaoWang", "age" : 25, "interest" : [ "写代码", "篮球" ] }
{ "name" : "LiangPeng", "age" : 28, "interest" : [ "玩游戏", "写代码" ] }
{ "name" : "HouFei", "age" : 25, "interest" : [ "化妆", "读书" ] }
{ "name" : "LiuYan", "age" : 35, "interest" : [ "画画", "聚会" ] }
{ "name" : "DingLu", "age" : 20, "interest" : [ "美食", "看电影" ] }
{ "name" : "JiaPeng", "age" : 29, "interest" : [ "写代码", "篮球" ] }
{ "name" : "LiJia", "age" : 26, "interest" : [ "玩游戏", "美食" ] }
>


// 如果我们想显示兴趣的最后一项，可以直接使用slice:-1，来进行查询。
> db.workmate.find(
...     {},
...     {name:1,interest:{$slice:-1},age:1,_id:0}
... )
{ "name" : "JSPang", "age" : 33, "interest" : [ "旅游" ] }
{ "name" : "ShengLei", "age" : 31, "interest" : [ "做饭" ] }
{ "name" : "MinJie", "age" : 18, "interest" : [ "看电影" ] }
{ "name" : "XiaoWang", "age" : 25, "interest" : [ "画画" ] }
{ "name" : "LiangPeng", "age" : 28, "interest" : [ "做饭" ] }
{ "name" : "HouFei", "age" : 25, "interest" : [ "做饭" ] }
{ "name" : "LiuYan", "age" : 35, "interest" : [ "看电影" ] }
{ "name" : "DingLu", "age" : 20, "interest" : [ "做饭" ] }
{ "name" : "JiaPeng", "age" : 29, "interest" : [ "游泳" ] }
{ "name" : "LiJia", "age" : 26, "interest" : [ "篮球" ] }
>
    find参数使用

    find方法的第一个参数（query）和第二个参数（fields）

    • find参数：
    1. query：这个就是查询条件，MongoDB默认的第一个参数。
    2. fields：（返回内容）查询出来后显示的结果样式，可以用true和false控制是否显示。
    3. limit：返回的数量，后边跟数字，控制每次查询返回的结果数量。
    4. skip:跳过多少个显示，和limit结合可以实现分页。
    5. sort：排序方式，从小到大排序使用1，从大到小排序使用-1。

    $where修饰符

    db.workmate.find(
    {$where:"this.age>30"},
    {name:true,age:true,_id:false}
)
    js文件使用find（）
    var db = connect("company")  //进行链接对应的集合collections
var result = db.workmate.find() //声明变量result，并把查询结果赋值给result
//利用游标的hasNext()进行循环输出结果。
while(result.hasNext()){
    printjson(result.next())  //用json格式打印结果
}
    var db = connect("company")  //进行链接对应的集合collections
var result = db.workmate.find() //声明变量result，并把查询结果赋值给result
//利用游标的hasNext()进行循环输出结果。
result.forEach(function(result){
    printjson(result)
})
    到此mongoDB的基础操作就结束了，但是我们还没有结束呢，下一节我们会用nodejs配合Mongodb使用哦~~
    mongodb
    Meils
    1.6k 声望157 粉丝

    前端开发实践者

    « 上一篇
    MongoDB （ 三 ）高级_状态返回和安全
    下一篇 »
    NodeJs 使用 Mongodb

    引用和评论

    推荐阅读
    头像
    微信小程序知识点总结（一）

    Meils赞 1阅读 6k

    头像
    MongoDB 8.0已全面可用

    MongoDB数据平台阅读 11.3k

    头像
    阿里云ECS服务器部署Node.js项目全过程详解

    kovli赞 1阅读 5.2k

    头像
    简道云搭载阿里云MongoDB数据库，帮助数以万计企业重构业务系统

    MongoDB数据平台阅读 10.7k

    头像
    利用MongoDB进行数据治理，防范构建生成式AI应用程序时的潜在安全风险

    MongoDB数据平台阅读 9.3k

    头像
    使用 MongoDB 构建 AI：Patronus 如何自动进行大语言模型评估来增强对生成式 AI 的信心

    MongoDB数据平台阅读 7.2k

    头像
    使用 MongoDB 构建 AI：Flagler Health 的 AI 旅程如何彻底改变患者护理

    MongoDB数据平台阅读 5.2k

    0 条评论
    得票最新