mongodb 常用操作

db.test.insert({title: "1111111111111111111"})  

for (var i = 0; i < 100; i++) {  
  db.test.insert({title: i * 1000})  
}  

db.test.insert([{title: "aaaaaaaaaaaaa"}, {title: "bbbbbbbbbbbb"}]) 

for (var i = 0; i < 100; i++) {
  db.test.insert({age: Math.round(Math.random() * 100)});
}

db.test.aggregate([{$group: {_id: "$age", count: {$sum: 1}}}])

db.test.find()  

db.test.find({title: {$gt: 90000}})  

db.test.find({title: {$gt: 90000, $lt: 93000}})  

db.test.findOne()  

db.test.find({name: {$exists: true}})  

db.posts.find({pv: {$gt: 100}}, {title: 1}).pretty()  

db.posts.count({pv: {$gt: 100}})  

db.posts.find({pv: {$gt: 100}, title:/mongo/}).pretty()  

$eq:等于  
$gt:大于  
$gte:大于等于  
$in:匹配数组中指定的任何值  
$lt:大于  
$lte:小于等于  
$ne:匹配不等于指定值的所有值  
$nin:不匹配数组中指定的值  
$size:数量为n的数组  
$exists:查询存在某个字段  
$type:检索集合中匹配的数据类型  

db.test.remove({title: {$gte: 2000}})  

db.test.remove({})  

db.test.find().limit(2)  

db.test.find().skip(2)

db.test.find().sort({title: 1})  

db.test.distinct("title")  

db.test.getIndexes()

[
        {
                "v" : 2,
                "key" : {
                        "_id" : 1
                },
                "name" : "_id_",
                "ns" : "nodeblog.test"
        },
        {
                "v" : 2,
                "key" : {
                        "title" : 1,
                        "count" : 1
                },
                "name" : "title_1_count_1",
                "ns" : "nodeblog.test"
        }
]

db.test.dropIndex("title_1_count_1")

db.test.createIndex({title: 1})  

db.test.createIndex({title: 1, count: 1})  

如：db.test.find({title: "hello99999"}).explain("executionStats")  

db.test.remove({count: {$gt: 10}})