MongoDB （ 四 ）高级_find修饰符

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Meils
    阅读 10 分钟
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    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
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