MongoDB v4.0 命令

MongoDB v4.0 命令 官方文档 > 点这里 < 操作系统库 #操作管理员库 use admin #鉴权 db.auth("root","admin"); #用户查看(格式美化) db.system.users.find().pretty(); #新增用户 db.createUser({ user: 'root1', pwd: 'admin1', roles: [ { role: "dbOwner", db: "yapi" }] }); #更新用户信息/密码/权限 db.updateUser("root1",{ pwd: "admin2", roles: [{ role: "root", db: "admin" },{ role: "userAdminAnyDatabase", db: "admin" },{ role: "readWriteAnyDatabase", db: "admin" },{ role: "dbAdminAnyDatabase", db: "admin" }]}) #删除数据库所属用户 db.dropUser("root1"); 操作自定义库 #操作自定义库 use persionalDB #鉴权 db.auth("user","pwd"); #创建数据库所属用户 db.createUser({ user: 'username1', pwd: 'password1', roles: [ { role: "dbOwner", db: "yapi" }] }); #更新用户信息/密码/权限 db.updateUser("username1",{ pwd: "NEW pass", roles: [{ role: "root", db: "admin" },{ role: "userAdminAnyDatabase", db: "admin" },{ role: "readWriteAnyDatabase", db: "admin" },{ role: "dbAdminAnyDatabase", db: "admin" }]}); #删除数据库所属用户 db.dropUser("username1"); 1.0.0 基础操作 [collection]= 所查集合名 use [db_name]; db.[collection].insert({[title]:'[value]'}); eg: db.hellocollction.insert({name:'hello'}); # 单个插入 db.inventory.insertOne( { item: "canvas", qty: 100, tags: ["cotton"], size: { h: 28, w: 35.5, uom: "cm" } } ) # 批量插入 db.inventory.insertMany([ { item: "journal", qty: 25, tags: ["blank", "red"], size: { h: 14, w: 21, uom: "cm" } }, { item: "mat", qty: 85, tags: ["gray"], size: { h: 27.9, w: 35.5, uom: "cm" } }, { item: "mousepad", qty: 25, tags: ["gel", "blue"], size: { h: 19, w: 22.85, uom: "cm" } } ]) 1.1 ============>增<============

db.[collection].insertOne()/insertMany()

1.2 ============>查<============

db.[[collection]].find()

1.3 ============>改<============

db.[collection].updateOne()/updateMany()/replaceOne()

1.4 ============>删<============

db.collection.deleteOne()/deleteMany()

2.0 高级: 联表查询 Join

初始数据

db.product.insert({"_id":1,"productname":"商品1","price":15}); db.product.insert({"_id":2,"productname":"商品2","price":36}); db.order.insert({"_id":1,"pid":1,"ordername":"订单1","uid":1}); db.order.insert({"_id":2,"pid":2,"ordername":"订单2","uid":2}); db.order.insert({"_id":3,"pid":2,"ordername":"订单3","uid":2}); db.order.insert({"_id":4,"pid":1,"ordername":"订单4","uid":1}); db.user.insert({"_id":1,"username":1}); db.user.insert({"_id":2,"username":2}); db.product.find(); db.order.find(); db.user.find();

2.1 $lookup 两表关联join

db.product.aggregate([ { $lookup: { from: "order", localField: "_id", foreignField: "pid", as: "inventory_docs" } } ]); #结果: { "_id" : 1.0, "productname" : "商品1", "price" : 15.0, "inventory_docs" : [ { "_id" : 1.0, "pid" : 1.0, "ordername" : "订单1" }, { "_id" : 4.0, "pid" : 1.0, "ordername" : "订单4" } ] }

lookup 就是使用 aggregate 的 $lookup 属性，$lookup 操作需要一个四个参数的对象：

localField：在输入文档中的查找字段

from：需要连接的集合

foreignField：需要在from集合中查找的字段

as：输出的字段名字

2.2 $lookup 三表关联join

db.order.aggregate([ { "lookup": { "from": "product", "localField": "pid", "foreignField": "_id", "as": "inventory_docs" } },{ "lookup": { "from": "user", "localField": "uid", "foreignField": "_id", "as": "user_docs" } } ]); 除了 $lookup，populate 也可以用来进行关联查询