MongoDB-Manual-Master 读书笔记-CRUD操作
3.1 MongoDB CRUD介绍从网址
https://raw.githubusercontent.com/mongodb/docs-assets/primer-dataset/dataset.json 下载示例文件
使用如下命令导入MongoDB，数据库test 集合名restaurants 。
# mongoimport --db test --collection restaurants --drop --file dataset.txt
2016-01-04T20:16:05.541+0800connected to: localhost
2016-01-04T20:16:05.543+0800dropping: test.restaurants
2016-01-04T20:16:08.362+0800imported 25359 documents
使用mongo客户端程序连接MongoDB
# mongo
MongoDB shell version: 3.2.0
connecting to: test
默认连接到test数据库，可以使用use命令切换数据库（指定的数据库没有时，则创建）
> use test_db
switched to db test_db
mongodb启动时默认监听的IP地址为127.0.0.1 如果需要网络访问mongodb，则修改配置文件/etc/mongod.conf
# network interfaces
net:
port: 27017
bindIp: 192.168.199.219
前面讲过MongoDB使用文档结构来存储数据，文档是一张类JSON的格式。严格来说，MongoDB使用BSON来存储数据，BSON是JSON的二进制表现形式。
所有的文档存在一个称之为Collections中，一个collection由一组相关的文档组成。你可以把collection看成关系数据库的表。
3.1.1 数据库操作
Query
MongoDB中使用db.collection.find()检索数据，collection表示具体的集合的名称。
此方法接受两个参数：查询条件、查询结果列（数据映射），并且返回一个cursor 。
上图表示在users集合中查询条件满足age>=18的，并且返回name，address列，返回结果只取5行数据。
projection部分，如果指定{name:0}则表示除去name的所有列。
其对应的SQL写法为：
db.collection.findOne()则只返回第一条数据
示例：
> db.restaurants.findOne()
{
"_id" : ObjectId("568a628607ce6e1e3c2e0a25"),
"address" : {
"building" : "1007",
"coord" : [
-73.856077,
40.848447
],
"street" : "Morris Park Ave",
"zipcode" : "10462"
},
"borough" : "Bronx",
"cuisine" : "Bakery",
"grades" : [
{
"date" : ISODate("2014-03-03T00:00:00Z"),
"grade" : "A",
"score" : 2
},
{
"date" : ISODate("2013-09-11T00:00:00Z"),
"grade" : "A",
"score" : 6
},
{
"date" : ISODate("2013-01-24T00:00:00Z"),
"grade" : "A",
"score" : 10
},
{
"date" : ISODate("2011-11-23T00:00:00Z"),
"grade" : "A",
"score" : 9
},
{
"date" : ISODate("2011-03-10T00:00:00Z"),
"grade" : "B",
"score" : 14
}
],
"name" : "Morris Park Bake Shop",
"restaurant_id" : "30075445"
}
查询address.building = 1008的
> db.restaurants.findOne({"address.building":"1008"})
{
"_id" : ObjectId("568a628607ce6e1e3c2e0b1b"),
"address" : {
"building" : "1008",
"coord" : [
-73.9668354,
40.7568328
],
"street" : "2 Avenue",
"zipcode" : "10022"
},
"borough" : "Manhattan",
"cuisine" : "French",
"grades" : [
{
"date" : ISODate("2014-02-04T00:00:00Z"),
"grade" : "A",
"score" : 11
},
{
"date" : ISODate("2013-04-10T00:00:00Z"),
"grade" : "A",
"score" : 7
},
{
"date" : ISODate("2012-02-27T00:00:00Z"),
"grade" : "A",
"score" : 10
},
{
"date" : ISODate("2011-11-02T00:00:00Z"),
"grade" : "A",
"score" : 4
},
{
"date" : ISODate("2011-07-11T00:00:00Z"),
"grade" : "A",
"score" : 9
},
{
"date" : ISODate("2011-03-07T00:00:00Z"),
"grade" : "C",
"score" : 39
}
],
"name" : "La Mangeoire",
"restaurant_id" : "40368971"
}
只选择grades字段
> db.restaurants.findOne({"address.building":"1008"},{"grades":1})
{
"_id" : ObjectId("568a628607ce6e1e3c2e0b1b"),
"grades" : [
{
"date" : ISODate("2014-02-04T00:00:00Z"),
"grade" : "A",
"score" : 11
},
{
"date" : ISODate("2013-04-10T00:00:00Z"),
"grade" : "A",
"score" : 7
},
{
"date" : ISODate("2012-02-27T00:00:00Z"),
"grade" : "A",
"score" : 10
},
{
"date" : ISODate("2011-11-02T00:00:00Z"),
"grade" : "A",
"score" : 4
},
{
"date" : ISODate("2011-07-11T00:00:00Z"),
"grade" : "A",
"score" : 9
},
{
"date" : ISODate("2011-03-07T00:00:00Z"),
"grade" : "C",
"score" : 39
}
]
}
显示除了grades的其他字段
> db.restaurants.findOne({"address.building":"1008"},{"grades":0})
{
"_id" : ObjectId("568a628607ce6e1e3c2e0b1b"),
"address" : {
"building" : "1008",
"coord" : [
-73.9668354,
40.7568328
],
"street" : "2 Avenue",
"zipcode" : "10022"
},
"borough" : "Manhattan",
"cuisine" : "French",
"name" : "La Mangeoire",
"restaurant_id" : "40368971"
查询zipcode=10022 并且cuisine="French"的
> db.restaurants.findOne({"address.zipcode":"10022","cuisine":"French"})
{
"_id" : ObjectId("568a628607ce6e1e3c2e0a85"),
"address" : {
"building" : "3",
"coord" : [
-73.97557069999999,
40.7596796
],
"street" : "East 52 Street",
"zipcode" : "10022"
},
"borough" : "Manhattan",
"cuisine" : "French",
"grades" : [
{
"date" : ISODate("2014-04-09T00:00:00Z"),
"grade" : "A",
"score" : 10
},
{
"date" : ISODate("2013-03-05T00:00:00Z"),
"grade" : "A",
"score" : 9
},
{
"date" : ISODate("2012-02-02T00:00:00Z"),
"grade" : "A",
"score" : 13
}
],
"name" : "La Grenouille",
"restaurant_id" : "40365264"
}
查询zipcode=10022 或者 cuisine="French"的
> db.restaurants.findOne({"$or":[{"address.zipcode":"10022"},{"cuisine":"French"}]})
{
"_id" : ObjectId("568a628607ce6e1e3c2e0a51"),
"address" : {
"building" : "437",
"coord" : [
-73.975393,
40.757365
],
"street" : "Madison Avenue",
"zipcode" : "10022"
},
"borough" : "Manhattan",
"cuisine" : "American ",
"grades" : [
{
"date" : ISODate("2014-06-03T00:00:00Z"),
"grade" : "A",
"score" : 9
},
{
"date" : ISODate("2013-06-07T00:00:00Z"),
"grade" : "A",
"score" : 5
},
{
"date" : ISODate("2012-06-29T00:00:00Z"),
"grade" : "A",
"score" : 12
},
{
"date" : ISODate("2012-02-06T00:00:00Z"),
"grade" : "A",
"score" : 11
},
{
"date" : ISODate("2011-06-23T00:00:00Z"),
"grade" : "A",
"score" : 13
}
],
"name" : "Berkely",
"restaurant_id" : "40363685"
}
查询grades.score大于13的
> db.restaurants.findOne({"grades.score":{"$gt":13}})
{
"_id" : ObjectId("568a628607ce6e1e3c2e0a25"),
"address" : {
"building" : "1007",
"coord" : [
-73.856077,
40.848447
],
"street" : "Morris Park Ave",
"zipcode" : "10462"
},
"borough" : "Bronx",
"cuisine" : "Bakery",
"grades" : [
{
"date" : ISODate("2014-03-03T00:00:00Z"),
"grade" : "A",
"score" : 2
},
{
"date" : ISODate("2013-09-11T00:00:00Z"),
"grade" : "A",
"score" : 6
},
{
"date" : ISODate("2013-01-24T00:00:00Z"),
"grade" : "A",
"score" : 10
},
{
"date" : ISODate("2011-11-23T00:00:00Z"),
"grade" : "A",
"score" : 9
},
{
"date" : ISODate("2011-03-10T00:00:00Z"),
"grade" : "B",
"score" : 14
}
],
"name" : "Morris Park Bake Shop",
"restaurant_id" : "30075445"
}
Insert
MongoDB中使用如下方法插入数据
db.collection.insertOne()
db.collection.insertMany()
db.collection.insert()
db.collection.insertOne() 3.2 新增方法
上图表示往users集合中插入一个文档
与如下图中的SQL语句等效
> db.users.insertOne({
... name:"dinglq",
... age:26
... ,status:"A",
... groups:["news","sports"]
... })
{
"acknowledged" : true,
"insertedId" : ObjectId("568a84a5a3e3eabd25b468af")
}
db.collection.insertMany() 是3.2版本新增功能，一次插入多个文档
> db.users.insertMany([
{name:"dinglq", age:26 ,status:"A", groups:["news","sports"]},
{name:"zhangdd",age:30,status:"B"},
{name:"vincent",age:44}])
{
"acknowledged" : true,
"insertedIds" : [
ObjectId("568a85ada3e3eabd25b468b0"),
ObjectId("568a85ada3e3eabd25b468b1"),
ObjectId("568a85ada3e3eabd25b468b2")
]
}
db.collection.insert() 向集合中添加一个文档，或者一组文档。
update
db.collection.updateOne()
db.collection.updateMany()
db.collection.replaceOne()
db.collection.update()
db.collection.updateOne() 3.2新增方法，只更新目中数据的第一条
更新users集合，条件是age db.users.updateOne({name:"dinglq"},{"$set":{"age":36}})
{ "acknowledged" : true, "matchedCount" : 1, "modifiedCount" : 1 }
> db.users.find({name:"dinglq"})
{ "_id" : ObjectId("568a84a5a3e3eabd25b468af"), "name" : "dinglq", "age" : 36, "status" : "A", "groups" : [ "news", "sports" ] }
{ "_id" : ObjectId("568a85ada3e3eabd25b468b0"), "name" : "dinglq", "age" : 26, "status" : "A", "groups" : [ "news", "sports" ] }
> db.users.updateMany({name:"dinglq"},{"$inc":{"age":4}})
{ "acknowledged" : true, "matchedCount" : 2, "modifiedCount" : 2 }
> db.users.find({name:"dinglq"})
{ "_id" : ObjectId("568a84a5a3e3eabd25b468af"), "name" : "dinglq", "age" : 40, "status" : "A", "groups" : [ "news", "sports" ] }
{ "_id" : ObjectId("568a85ada3e3eabd25b468b0"), "name" : "dinglq", "age" : 30, "status" : "A", "groups" : [ "news", "sports" ] }
使用$push向数组类型的数据添加元素。
> db.users.findOne()
{
"_id" : ObjectId("568a84a5a3e3eabd25b468af"),
"name" : "dinglq",
"age" : 40,
"status" : "A",
"groups" : [
"news",
"sports"
]
}
> db.users.updateOne({"name":"dinglq"},{"$push":{"groups":"reading"} })
{ "acknowledged" : true, "matchedCount" : 1, "modifiedCount" : 1 }
> db.users.findOne()
{
"_id" : ObjectId("568a84a5a3e3eabd25b468af"),
"name" : "dinglq",
"age" : 40,
"status" : "A",
"groups" : [
"news",
"sports",
"reading"
]
}
使用$push添加元素时，不会检查该值是否存在，例如
> db.users.updateOne({"name":"dinglq"},{"$push":{"groups":"reading"} })
{ "acknowledged" : true, "matchedCount" : 1, "modifiedCount" : 1 }
> db.users.findOne()
{
"_id" : ObjectId("568a84a5a3e3eabd25b468af"),
"name" : "dinglq",
"age" : 40,
"status" : "A",
"groups" : [
"news",
"sports",
"reading",
"reading"
]
}
可见，groups中有两个"reading"的值。
如何避免呢？
> db.users.updateOne({"name":"dinglq"},{"$addToSet":{"groups":"news"} })
{ "acknowledged" : true, "matchedCount" : 1, "modifiedCount" : 0 }
使用$addToSet时，会检查该值是否存在，存在则不再插入。
使用$pop从数组的尾部或头部删除内容
> db.users.updateOne({"name":"dinglq"},{"$pop":{"groups":1}})
{ "acknowledged" : true, "matchedCount" : 1, "modifiedCount" : 1 }
> db.users.findOne({"name":"dinglq"})
{
"_id" : ObjectId("568a84a5a3e3eabd25b468af"),
"name" : "dinglq",
"age" : 40,
"status" : "A",
"groups" : [
"news",
"sports",
"reading"
]
}
如果想从数组头部开始删除数据
> db.users.updateOne({"name":"dinglq"},{"$pop":{"groups":-1}})
{ "acknowledged" : true, "matchedCount" : 1, "modifiedCount" : 1 }
> db.users.findOne({"name":"dinglq"})
{
"_id" : ObjectId("568a84a5a3e3eabd25b468af"),
"name" : "dinglq",
"age" : 40,
"status" : "A",
"groups" : [
"sports",
"reading"
]
}
指定数组中的内容删除
> db.users.updateOne({"name":"dinglq"},{"$pull":{"groups":"sports"}})
{ "acknowledged" : true, "matchedCount" : 1, "modifiedCount" : 1 }
db.collection.updateMany() 3.2新增方法，更新命中的所有文档
db.collection.replaceOne() 3.2新增方法，使用新指定的文档替换命中的第一个文档
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