Mongodb-基本命令
分类:Mongdb
1.回顾:上篇已经学习过 Mongodb的安装的两种方式
2.这篇将学习 mongodb的基本命令
3.准备 :安装好mongodb后,需要先打开mongodb服务,后打开一个客户端 (cmd操作)
4.创建数据库,对象和集合
4.1 新建数据库 db
use student
4.2 新建集合 Collection
db.createCollection("LABELNET");
4.3 新建 文档 document
document={"name":"yuan","age":23} 4.4 查看所有数据库show dbs
4.5 查看一个数据库下的集合状态
use student;db.printCollectionStats();
4.6 演示结果:
> use studentswitched to db student> db.createCollection("LABELNET");{ "ok" : 1 }> document={"name":"yuan","age":23}{ "name" : "yuan", "age" : 23 }> show dbslocal 0.078GBstudent 0.078GB> use studentswitched to db student> db.printCollectionStats();LABELNET{"ns" : "student.LABELNET","count" : 0,"size" : 0,"numExtents" : 1,"storageSize" : 8192,"lastExtentSize" : 8192,"paddingFactor" : 1,"paddingFactorNote" : "paddingFactor is unused and unmaintained in 3.0.It remains hard coded to 1.0 for compatibility only.","userFlags" : 1,"capped" : false,"nindexes" : 1,"totalIndexSize" : 8176,"indexSizes" : {"_id_" : 8176},"ok" : 1}—system.indexes{"ns" : "student.system.indexes","count" : 1,"size" : 112,"avgObjSize" : 112,"numExtents" : 1,"storageSize" : 8192,"lastExtentSize" : 8192,"paddingFactor" : 1,"paddingFactorNote" : "paddingFactor is unused and unmaintained in 3.0.It remains hard coded to 1.0 for compatibility only.","userFlags" : 0,"capped" : false,"nindexes" : 0,"totalIndexSize" : 0,"indexSizes" : {},"ok" : 1}—>5. 插入操作 insert
5.1 可以先定义一个文档document ,后将文档插入到集合中。或者直接将输入插入到集合中。
5.2 基本格式
db.集合名称.insert(已定义的文档);
db.集合名称.insert(数据);
5.3 演示示例
—> db.LABELNET.insert({"name":"csdn","age":"老大了!"});WriteResult({ "nInserted" : 1 })> document={"name":"yuan",age:"23"};{ "name" : "yuan", "age" : "23" }> db.LABELNET.insert(document);WriteResult({ "nInserted" : 1 })
6. 查询操作 find
6.1 基本格式
(1)db.集合名称.find();显示文档
(2)db.集合名称.find(where);
(3)db.集合名称.find({"name":{$type:2}});
6.2 基本查询
> db.LABELNET.find();{ "_id" : ObjectId("55bec40532cbb5faa25c967c"), "name" : "csdn", "age" : "老大了!" }{ "_id" : ObjectId("55bec43732cbb5faa25c967d"), "name" : "yuan", "age" : "23" }
6.3 条件查询
$type操作符是基于BSON类型来检索集合中匹配的结果。
db.集合名称.find({"name":{$type:2}});
$type 对应得值 有下面几种:
Double 1 String 2 Object 3 Array 4 Binary data 5 Object id 7 Boolean 8Date 9Null 10Regular expression 11JavaScript code 13Symbol 14JavaScript code with scope 1532-bit integer 16Timestamp 1764-bit integer 18Min key 255Max key 127 演示示例:> db.LABELNET.find({"name":"yuan"});{ "_id" : ObjectId("55bec43732cbb5faa25c967d"), "name" : "yuan", "age" : "23" }> db.LABELNET.find({"name":{$type:2}});{ "_id" : ObjectId("55bec40532cbb5faa25c967c"), "name" : "csdn", "age" : "老大了!" }{ "_id" : ObjectId("55bec43732cbb5faa25c967d"), "name" : "yuan", "age" : "23" }>
6.4 满足条件的,取固定条数 : db.集合名称.find({条件}).limit(10);
7.修改数据 update
7.1基本格式 : 注意条件
db.集合名称.update(where,set,未找到插入新的为true,更新多条为true);
7.2 演示 示例 : 修改 name为csdn的 age值
你可以很有个性,但某些时候请收敛。