MongoDB数据库基础操作。，具体如下：
1.创建数据库
>use test
> db.test.insert({"name":1})
插入之后才能查到test
2.查看数据库
>show dbs
3.删除数据库
> use test > db.dropDatabase()
4.创建集合
4.1 集合概念
集合就是一组文档，相当于多条记录。
> db.title.insert({"name":"hyx"})
插入之后即创建集合
5.查看集合
> show collections
6.删除集合
>use test >db.title.drop()
7.插入文档
7.1 文档概念
多个键及其关联的值有序地放置在一起就是文档。 文档类似于json数据
> db.file.insert({name:"huangyuxin",age:11})
8.查看文档
>db.files.find()
9.变量方式插入文档
> document=({by:"hyx"})
{ "by" : "hyx" }
> db.file.insert(document)
WriteResult({ "nInserted" : 1 })
> db.file.find()
{ "_id" : ObjectId("5c6e8a060fc535200b893f29"), "name" : "huangyuxin", "age" : 11 }
{ "_id" : ObjectId("5c6e8b1c0fc535200b893f2a"), "by" : "hyx" }
>
10.同时插入多条
> var res = db.file.insertMany([{"b": 3}, {'c': 4}])
> res
{
"acknowledged" : true,
"insertedIds" : [
ObjectId("5c6e8bba0fc535200b893f2b"),
ObjectId("5c6e8bba0fc535200b893f2c")
]
}
> db.file.find()
{ "_id" : ObjectId("5c6e8a060fc535200b893f29"), "name" : "huangyuxin", "age" : 11 }
{ "_id" : ObjectId("5c6e8b1c0fc535200b893f2a"), "by" : "hyx" }
{ "_id" : ObjectId("5c6e8bba0fc535200b893f2b"), "b" : 3 }
{ "_id" : ObjectId("5c6e8bba0fc535200b893f2c"), "c" : 4 }
>
11.更新文档
> db.file.update({"name":"huangyuxin"},{$set:{"name":"hyx"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.file.find()
{ "_id" : ObjectId("5c6e8a060fc535200b893f29"), "name" : "hyx", "age" : 11 }
{ "_id" : ObjectId("5c6e8b1c0fc535200b893f2a"), "by" : "hyx" }
{ "_id" : ObjectId("5c6e8bba0fc535200b893f2b"), "b" : 3 }
{ "_id" : ObjectId("5c6e8bba0fc535200b893f2c"), "c" : 4 }
{ "_id" : ObjectId("5c6e8cdf0fc535200b893f2d"), "name" : "hyx" }
>
> db.file.save({"_id" : ObjectId("5c6e8b1c0fc535200b893f2a"),"name":"hyx"})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.file.find()
{ "_id" : ObjectId("5c6e8a060fc535200b893f29"), "name" : "hyx", "age" : 11 }
{ "_id" : ObjectId("5c6e8b1c0fc535200b893f2a"), "name" : "hyx" }
{ "_id" : ObjectId("5c6e8bba0fc535200b893f2b"), "b" : 3 }
{ "_id" : ObjectId("5c6e8bba0fc535200b893f2c"), "c" : 4 }
{ "_id" : ObjectId("5c6e8cdf0fc535200b893f2d"), "name" : "hyx" }
>
