mongo基本操作

• > db.per.find({$and:[{age:{$gt:5}},{age:{$lt:10}}]})//age大于5且小于10
  { "_id" : 6, "name" : "liu_6", "age" : 6 }
  { "_id" : 7, "name" : "liu_7", "age" : 7 }
  { "_id" : 8, "name" : "liu_8", "age" : 8 }
  { "_id" : 9, "name" : "liu_9", "age" : 9 }
  

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• > db.per.find({$nor:[{age:2}],$and:[{age:{$lt:5}}]});//age不等于2且小于5
  { "_id" : 0, "name" : "liu", "age" : 0, "addr" : [ "bj" ] }
  { "_id" : 1, "name" : "liu_1", "age" : 1 }
  { "_id" : 3, "name" : "liu_3", "age" : 3 }
  { "_id" : 4, "name" : "liu_4", "age" : 4 }
  

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• > db.per.find({addr:{$exists:1}});//是否存在
  { "_id" : 0, "name" : "liu", "age" : 0, "addr" : [ "bj" ] }

• db.per.insert({lili:hobby['a','b','c']});
  db.per.insert({lucy:hobby['b','c','d']});
  db.per.find({$all:{hobby:['b','c']}});

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• $gt >
•  $gte >=
•  $lt <
•  $lte <=
•  $in in
•  $ne !=
•  $nin not in

---

   for(var i=0;i<10000;i++){
        db.bar.insert({'_id':i+1,title:'aaa'+i})
    }

    var cursor = db.bar.find();
     cursor.next();

---

    
> var cur = db.per.find({age:{$lt:5}})
> printjson(cur.next());
{ "_id" : 0, "name" : "liu", "age" : 0, "addr" : [ "bj" ] }
> printjson(cur.next());
{ "_id" : 1, "name" : "liu_1", "age" : 1 }

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用循环来打印
var cur = db.find({age:{$lt:5}});
while(cur.hasNext()){

     printjson(cur.next());

}

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//forEach
> var cur = db.per.find({age:{$lt:5}});
> cur.forEach(function(obj){printjson(obj)});
{ "_id" : 0, "name" : "liu", "age" : 0, "addr" : [ "bj" ] }
{ "_id" : 1, "name" : "liu_1", "age" : 1 }
{ "_id" : 2, "name" : "liu_2", "age" : 2 }
{ "_id" : 3, "name" : "liu_3", "age" : 3 }
{ "_id" : 4, "name" : "liu_4", "age" : 4 }

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