MongoDB官网文档笔记 - MongoDB入门

1. shell连接MongoDB

   # mongo <host>/<db> -u <user> -p <password>
   mongo 192.168.1.200:27017/database  -u user  -p  password
   

2. 切换数据库：切换数据库之前不需要创建数据库，当第一次在数据库中存储数据时，MongoDB会自动创建数据库。

   # db指当前数据库，mongoDB默认是test数据库
   db
   # use <db>用于切换数据库，比如说切换到examples数据库：
   use examples
   

3. 插入集合：MongoDB将文档存储在集合中。集合类似于关系数据库中的表，如果数据库中不存在该集合，在第一次为该集合存储数据时，MongoDB会自动创建集合。db.collection.insertMany()可插入多条数据到集合中，如果_id字段在文档中不存在，MongoDB就使用ObjectId添加一个_id字段。该操作返回一个包含一个确认指示符acknowledged和包含每个成功插入的文档_id的数组文档。

   > db.inventory.insertMany([
    { item: "journal", qty: 25, status: "A", size: { h: 14, w: 21, uom: "cm" }, tags: [ "blank", "red" ] },
    { item: "notebook", qty: 50, status: "A", size: { h: 8.5, w: 11, uom: "in" }, tags: [ "red", "blank" ] },
    { item: "paper", qty: 10, status: "D", size: { h: 8.5, w: 11, uom: "in" }, tags: [ "red", "blank", "plain" ] },
    { item: "planner", qty: 0, status: "D", size: { h: 22.85, w: 30, uom: "cm" }, tags: [ "blank", "red" ] },
    { item: "postcard", qty: 45, status: "A", size: { h: 10, w: 15.25, uom: "cm" }, tags: [ "blue" ] }
   ]);
   {
   	"acknowledged" : true,
   	"insertedIds" : [
   		ObjectId("5e106095fa6c58a3116cee8b"),
   		ObjectId("5e106095fa6c58a3116cee8c"),
   		ObjectId("5e106095fa6c58a3116cee8d"),
   		ObjectId("5e106095fa6c58a3116cee8e"),
   		ObjectId("5e106095fa6c58a3116cee8f")
   	]
   }  
   

4. 查找文档：db.collection.find()用于从集合中查找文档，过滤条件传空用于查找所有的文档。find()操作后添加.pretty()可格式化输出。

   # 查找所有的文档
   > db.inventory.find({})
   { "_id" : ObjectId("5e106095fa6c58a3116cee8b"), "item" : "journal", "qty" : 25, "status" : "A", "size" : { "h" : 14, "w" : 21, "uom" : "cm" }, "tags" : [ "blank", "red" ] }
   { "_id" : ObjectId("5e106095fa6c58a3116cee8c"), "item" : "notebook", "qty" : 50, "status" : "A", "size" : { "h" : 8.5, "w" : 11, "uom" : "in" }, "tags" : [ "red", "blank" ] }
   { "_id" : ObjectId("5e106095fa6c58a3116cee8d"), "item" : "paper", "qty" : 10, "status" : "D", "size" : { "h" : 8.5, "w" : 11, "uom" : "in" }, "tags" : [ "red", "blank", "plain" ] }
   { "_id" : ObjectId("5e106095fa6c58a3116cee8e"), "item" : "planner", "qty" : 0, "status" : "D", "size" : { "h" : 22.85, "w" : 30, "uom" : "cm" }, "tags" : [ "blank", "red" ] }
   { "_id" : ObjectId("5e106095fa6c58a3116cee8f"), "item" : "postcard", "qty" : 45, "status" : "A", "size" : { "h" : 10, "w" : 15.25, "uom" : "cm" }, "tags" : [ "blue" ] }
   
   # 格式化输出
   > db.inventory.find({}).pretty()
   {
   	"_id" : ObjectId("5e106095fa6c58a3116cee8b"),
   	"item" : "journal",
   	"qty" : 25,
   	"status" : "A",
   	"size" : {
   		"h" : 14,
   		"w" : 21,
   		"uom" : "cm"
   	},
   	"tags" : [
   		"blank",
   		"red"
   	]
   }
   {
   	"_id" : ObjectId("5e106095fa6c58a3116cee8c"),
   	"item" : "notebook",
   	"qty" : 50,
   	"status" : "A",
   	"size" : {
   		"h" : 8.5,
   		"w" : 11,
   		"uom" : "in"
   	},
   	"tags" : [
   		"red",
   		"blank"
   	]
   }
   {
   	"_id" : ObjectId("5e106095fa6c58a3116cee8d"),
   	"item" : "paper",
   	"qty" : 10,
   	"status" : "D",
   	"size" : {
   		"h" : 8.5,
   		"w" : 11,
   		"uom" : "in"
   	},
   	"tags" : [
   		"red",
   		"blank",
   		"plain"
   	]
   }
   {
   	"_id" : ObjectId("5e106095fa6c58a3116cee8e"),
   	"item" : "planner",
   	"qty" : 0,
   	"status" : "D",
   	"size" : {
   		"h" : 22.85,
   		"w" : 30,
   		"uom" : "cm"
   	},
   	"tags" : [
   		"blank",
   		"red"
   	]
   }
   {
   	"_id" : ObjectId("5e106095fa6c58a3116cee8f"),
   	"item" : "postcard",
   	"qty" : 45,
   	"status" : "A",
   	"size" : {
   		"h" : 10,
   		"w" : 15.25,
   		"uom" : "cm"
   	},
   	"tags" : [
   		"blue"
   	]
   }
   

5. 指定相等匹配：在db.collection.find()方法查询时使用<field>: <value>形式可指定相等匹配条件。

   • 匹配的field为字符串类型，value也为字符串，则为相等匹配，如db.inventory.find( { status: "D" } )表示status等于D的文档记录。
   • 匹配的field为嵌入式文档类型，value也为嵌入式文档类型，则也为相等匹配，嵌入式文档的匹配要求完全匹配，包括嵌入式文档中的字段顺序。如db.inventory.find( { size: { h: 14, w: 21, uom: "cm" } } )表示size等于{ h: 14, w: 21, uom: "cm" } 的文档记录。
   • 匹配的field为数组类型，value为字符串类型，则为包含匹配。如db.inventory.find( { tags: "red" } )表示tags中包含red的文档记录
   • 匹配的field为数组类型，value也为数组类型，则为相等匹配。如 db.inventory.find( { tags: [ "red", "blank" ] } )表示tags等于[ "red", "blank" ]的文档记录。

   # 查询inventory集合中status等于D的文档记录
   > db.inventory.find( { status: "D" } );
   { "_id" : ObjectId("5e106095fa6c58a3116cee8d"), "item" : "paper", "qty" : 10, "status" : "D", "size" : { "h" : 8.5, "w" : 11, "uom" : "in" }, "tags" : [ "red", "blank", "plain" ] }
   { "_id" : ObjectId("5e106095fa6c58a3116cee8e"), "item" : "planner", "qty" : 0, "status" : "D", "size" : { "h" : 22.85, "w" : 30, "uom" : "cm" }, "tags" : [ "blank", "red" ] }
   
   # 查询inventory集合中qty等于0的文档记录
   > db.inventory.find( { qty: 0 } );
   { "_id" : ObjectId("5e106095fa6c58a3116cee8e"), "item" : "planner", "qty" : 0, "status" : "D", "size" : { "h" : 22.85, "w" : 30, "uom" : "cm" }, "tags" : [ "blank", "red" ] }
   
   # 查询inventory集合中size等于文档{ h: 14, w: 21, uom: "cm" }的文档记录
   > db.inventory.find( { size: { h: 14, w: 21, uom: "cm" } } )
   { "_id" : ObjectId("5e106095fa6c58a3116cee8b"), "item" : "journal", "qty" : 25, "status" : "A", "size" : { "h" : 14, "w" : 21, "uom" : "cm" }, "tags" : [ "blank", "red" ] }
   
   # 查询inventory集合中tags数组中包含red的文档记录
   > db.inventory.find( { tags: "red" } )
   { "_id" : ObjectId("5e106095fa6c58a3116cee8b"), "item" : "journal", "qty" : 25, "status" : "A", "size" : { "h" : 14, "w" : 21, "uom" : "cm" }, "tags" : [ "blank", "red" ] }
   { "_id" : ObjectId("5e106095fa6c58a3116cee8c"), "item" : "notebook", "qty" : 50, "status" : "A", "size" : { "h" : 8.5, "w" : 11, "uom" : "in" }, "tags" : [ "red", "blank" ] }
   { "_id" : ObjectId("5e106095fa6c58a3116cee8d"), "item" : "paper", "qty" : 10, "status" : "D", "size" : { "h" : 8.5, "w" : 11, "uom" : "in" }, "tags" : [ "red", "blank", "plain" ] }
   { "_id" : ObjectId("5e106095fa6c58a3116cee8e"), "item" : "planner", "qty" : 0, "status" : "D", "size" : { "h" : 22.85, "w" : 30, "uom" : "cm" }, "tags" : [ "blank", "red" ] }
   
   # inventory集合中tags为["red", "blank"]的文档记录
   > db.inventory.find( { tags: [ "red", "blank" ] } )
   { "_id" : ObjectId("5e106095fa6c58a3116cee8c"), "item" : "notebook", "qty" : 50, "status" : "A", "size" : { "h" : 8.5, "w" : 11, "uom" : "in" }, "tags" : [ "red", "blank" ] }
   

6. 指定要返回的字段：使用db.collection.find(<query document>,<projection document> )方法传入一个投影文档，可以指定返回的字段。在投影文档中：

   • <field>: 1表示在文档返回中包含指定字段
   • <field>: 0表示在文档返回中排除指定字段

   返回文档中_id是默认返回的

   # 返回inventory集合中所有文档的_id,item和status字段
   > db.inventory.find( { }, { item: 1, status: 1 } );
   { "_id" : ObjectId("5e106095fa6c58a3116cee8b"), "item" : "journal", "status" : "A" }
   { "_id" : ObjectId("5e106095fa6c58a3116cee8c"), "item" : "notebook", "status" : "A" }
   { "_id" : ObjectId("5e106095fa6c58a3116cee8d"), "item" : "paper", "status" : "D" }
   { "_id" : ObjectId("5e106095fa6c58a3116cee8e"), "item" : "planner", "status" : "D" }
   { "_id" : ObjectId("5e106095fa6c58a3116cee8f"), "item" : "postcard", "status" : "A" }
   
   # 排除返回文档中的_id字段
   > db.inventory.find( {}, { _id: 0, item: 1, status: 1 } );
   { "item" : "journal", "status" : "A" }
   { "item" : "notebook", "status" : "A" }
   { "item" : "paper", "status" : "D" }
   { "item" : "planner", "status" : "D" }
   { "item" : "postcard", "status" : "A" }
   

原文地址：Getting Started