MongoDB

   $set: {name: "zhangsandege", sex: "female"},
     $push: {phoneNum: "186xxx"},
     $sort: {age: 1}
    }, false, true);
 - 查
  - 查询
   collections.find({name: "zhangsan"});
  - 游标（数组的引用）
   var cursor = studentsColl.find();
  - 显示数据
   var cursor = studentsColl.find();
   cursor.forEach(function(obj) {
    printjson(obj);
   });
  - 限制字段
   studentsColl.find(query, {name: 1, age: 0})
    - 1 表示显示该属性
    - 0 表示去掉该属性
  - 统计
   cursor.count();
  - 排序
   cursor.sort({name: 1, age: -1});
    -  1 升序
    - -1 降序
  - 正则
   {name: {$regex: /^zhang.{0,}$/}}
  - 分页
   cursor.limit(num);
    - num为限制数量
   cursor.skip(num);
    - num为跨过数量
   cursor.skip(0).limit(10);
   cursor.skip(10).limit(10);
  - 去重
   collection.distinct("name", {age: 18});
  - 分组
   var results = collections.group(
    {key: {name: 1, age: 0}},
    cond: {},
    initial: {count: 0, vowels: 0, consonants: 0},
    reduce: function(obj, prev) {
     prev.count++;
     prev.vowels += obj.stats.vowels;
     prev.consonants += obj.stats.consonants;
    },
    finalize: function(obj) {
     obj.total = obj.vowels + obj.consonants;
    }
   );
  - 聚合
   collections.aggregate({
    {$match: {sex: "male"}},
    {$group: {_id: "$className", largest: {$max: "$age"}, smallest: {$min: "$size"}},
    {$sort: {_id: 1}}}
   });
8.权限

MongoDB

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