mongodb的常用操作

1.与关系型数据库（MySQL）的对比

document（文档）<->  一行记录

collection（集合） <->  Table（表）

database（数据库）<-> database

 

2.crud操作

创建

> user = {'name': 'sosop', 'age': 18, 'gender': 'male'}
{ "name" : "sosop", "age" : 18, "gender" : "male" }
> db.users.insert(user)
WriteResult({ "nInserted" : 1 })

 查询

db.users.insert(user)
WriteResult({ "nInserted" : 1 })
> db.users.find()
{ "_id" : ObjectId("549557d23359eef64b07bb46"), "name" : "sosop", "age" : 18, "gender" : "male" }
> db.users.findOne()
{
	"_id" : ObjectId("549557d23359eef64b07bb46"),
	"name" : "sosop",
	"age" : 18,
	"gender" : "male"
}

 更新

user.birthday = new Date('1996-01-01')
ISODate("1996-01-01T00:00:00Z")
b.users.update({'name': 'sosop'},user)
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.users.find()
{ "_id" : ObjectId("549557d23359eef64b07bb46"), "name" : "sosop", "age" : 18, "gender" : "male", "birthday" : ISODate("1996-01-01T00:00:00Z") }

 删除

db.users.remove({'name': 'sosop'})
WriteResult({ "nRemoved" : 1 })

 

3.修改器的使用

$set：键不存在则创建，存在则修改

> db.users.find()
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 18, "gender" : "male", "birthday" : ISODate("1996-01-01T00:00:00Z") }
> db.users.update({'name': 'sosop'}, {$set: {'birthday': new Date('1996-03-11')}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.users.find()
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 18, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z") }
> db.users.update({'name': 'sosop'}, {$set: {'email': '[e-mail]'}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.users.find()
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 18, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]" }

 

$inc：增加减少

> db.users.update({'name': 'sosop'}, {$inc: {'age': 10}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.users.findOne()
{
	"_id" : ObjectId("549567573359eef64b07bb47"),
	"name" : "sosop",
	"age" : 28,
	"gender" : "male",
	"birthday" : ISODate("1996-03-11T00:00:00Z"),
	"email" : "[e-mail]"
}
> db.users.update({'name': 'sosop'}, {$inc: {'age': -2}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.users.find()
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]" }

 

$push

> db.users.update({'age': 26}, {$push: {'phone': "88888888888"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.users.find()
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "88888888888" ] 

 $addToSet

db.users.update({'name': 'sosop'}, {$addToSet: {'phone': '66666666666'}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.users.find()
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "88888888888", "66666666666" ] }
db.users.update({'name': 'sosop'}, {$addToSet: {'phone': {$each: ['99999999999', '000000000']}}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.users.find()
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "88888888888", "66666666666", "99999999999", "000000000" ] }

$pop：{key: 1} 从尾部删除 {key: -1}从头部删除

$pull：{key: value} 删除指定元素

 

数组定位修改器

db.users.update({'name': 'sosop'}, {$set: {'phone.$.xxx': 'xxx'}}

 

4.upsert更新或创建，同时避免静态

update({}, {}, true)

save: 存在时更新，否则插入

update({}, {}, true, true): 多文档更新

 

5.查询

find() find({}) find({}, {field: 1|0...})

> db.users.find({'age': {$gte: 18, $lte: 30}})
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "88888888888", "66666666666", "99999999999" ] }

$lt $gt $lte $gte $ne

$in $nin

db.users.find({'phone': {$in: ['666666666', '66666666666']}})
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "88888888888", "66666666666", "99999999999" ] }

$or

> db.users.find({$or: [{'name': 'sosop'}, {'age': 18}]})
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "88888888888", "66666666666", "99999999999" ] }

 

$not $mod

 

6.特定类型查询

null

> db.users.find({'name': {$exists: true}})
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "88888888888", "66666666666", "99999999999" ] }
> db.users.find({'addr': {$exists: true}})
> 

reg:

db.users.find({'name': /sosop/})
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "88888888888", "66666666666", "99999999999" ] }
db.users.find({'name': /\S/i})
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "88888888888", "66666666666", "99999999999" ] 

 数组查询

> db.users.find({'phone': {$all: ['88888888888', '99999999999']}})
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "88888888888", "66666666666", "99999999999" ] }

 

> db.users.find({'phone': {$size: 3}})
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "88888888888", "66666666666", "99999999999" ] }

 

> db.users.find({'name': 'sosop'},{'phone': {$slice: 1}})
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "88888888888" ] }
> db.users.find({'name': 'sosop'},{'phone': {$slice: 2}})
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "88888888888", "66666666666" ] }
> db.users.find({'name': 'sosop'},{'phone': {$slice: -1}})
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "99999999999" ] }
> db.users.find({'name': 'sosop'},{'phone': {$slice: [2,3]}})
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "99999999999" ] }
> db.users.find({'name': 'sosop'},{'phone': {$slice: [1,2]}})
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "66666666666", "99999999999" ] }

 内嵌文档

db.users.find({'addr.city': 'Chengdu'})
db.users.find({'addr': {$elemMatch: {'city': 'Chengdu', 'country': 'China'}}})

 

 $where查询比常规长训慢

 

7.游标

> var cursor = db.users.find()
> while(cursor.hasNext()) {
... u = cursor.next()
... print(u.name)
... }
sosop
> cursor.forEach(function(u) {
... print(u.age)
... }
... )

 limit skip sort

> db.users.find()
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "88888888888", "66666666666", "99999999999" ] }
{ "_id" : ObjectId("549577f83359eef64b07bb48"), "name" : "net-sosop", "age" : 27, "gender" : "male", "birthday" : ISODate("1996-01-01T00:00:00Z") }
> db.users.find().limit(1)
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "88888888888", "66666666666", "99999999999" ] }
> db.users.find().skip(1)
{ "_id" : ObjectId("549577f83359eef64b07bb48"), "name" : "net-sosop", "age" : 27, "gender" : "male", "birthday" : ISODate("1996-01-01T00:00:00Z") }
> db.users.find().sort({'age': 1})
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "88888888888", "66666666666", "99999999999" ] }
{ "_id" : ObjectId("549577f83359eef64b07bb48"), "name" : "net-sosop", "age" : 27, "gender" : "male", "birthday" : ISODate("1996-01-01T00:00:00Z") }
> db.users.find().sort({'age': -1})
{ "_id" : ObjectId("549577f83359eef64b07bb48"), "name" : "net-sosop", "age" : 27, "gender" : "male", "birthday" : ISODate("1996-01-01T00:00:00Z") }
{ "_id" : ObjectId("549567573359eef64b07bb47"), "name" : "sosop", "age" : 26, "gender" : "male", "birthday" : ISODate("1996-03-11T00:00:00Z"), "email" : "[e-mail]", "phone" : [ "88888888888", "66666666666", "99999999999" ] }

 避免使用skip过滤大量数据

 

8.高级查询

$maxscan : integer

$max : document

$min :document

$explain: boolean

$hint: documnet

$snapshot: boolean

 

9.索引

建立索引

db.users.ensureIndex({'name': 1})

 注意多键创建索引时，索引的方向

索引缺点：每次cud时都会有额外的开销

索引名称：

db.users.ensureIndex({'name': 1}， {‘name’: 'name'm 'unique': true, 'dropDups': true})

 explain和hint

db.users.find().explain()

 

10.地理空间索引

db.users.ensureIndex({'gps': '2d'}, {$min: 100,$max: 1000})
db.users.find({'gps': {$near: [200,80]}})

 $within $box $center

 

11.聚合

count

db.users.count({})

group

db.users.group({key: {age: true}, initial: {"age": 0}, $reduce: function(doc, prev){ if (doc.age > prev.age) { prev.age = doc.age }}, condition: {age: {$gt: 26}}})

 finalize完成器

 函数作为键：$keyf: function(x) {}

 

MapReduce:

并行化到多个服务器的聚合方法

map reduce finalize keeptemp output query limit sort scope  verbose

db.users.mapReduce(map, reduce, {out: 'tmp', sort: {age: 1}, limit: 1}