MongoDb 操作数据库

1，连接数据库：

cmd 进入终端，输入 mongo

输入 show dbs 可以看到所以的数据库：

 刚开始会有这三个数据库

2，创建数据库（加入创建一个 hello 的数据库）

需要 往 hello 数据库的 user 集合中插入一条数据，数据库才真正创建成功

3，插入（增加）数据

db.user.insert ( { " name " : " jack " })

for 循环可以添加多条数据：

4，显示当前的数据集合：

 5，查询所有记录：

db.user.find( ) 

6，查询 age=18的记录：

7，查询 age>18 的记录：

8，查询 age<18 的记录：

9，查询 age>=18的记录：

10，查询age<=18的记录

 11，查询 age >=18 小于23的记录：

 12，查询 name 中包含 8 的数据：

 13，查询 name 中以 Jack 开头的：

> db.user.find({"name":/^jack/})
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a0"), "ID" : 1, "name" : "jack1", "age" : 6 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a1"), "ID" : 2, "name" : "jack2", "age" : 7 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a2"), "ID" : 3, "name" : "jack3", "age" : 8 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a3"), "ID" : 4, "name" : "jack4", "age" : 9 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a4"), "ID" : 5, "name" : "jack5", "age" : 10 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a5"), "ID" : 6, "name" : "jack6", "age" : 11 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a6"), "ID" : 7, "name" : "jack7", "age" : 12 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a7"), "ID" : 8, "name" : "jack8", "age" : 13 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a8"), "ID" : 9, "name" : "jack9", "age" : 14 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a9"), "ID" : 10, "name" : "jack10", "age" : 15 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2aa"), "ID" : 11, "name" : "jack11", "age" : 16 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ab"), "ID" : 12, "name" : "jack12", "age" : 17 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ac"), "ID" : 13, "name" : "jack13", "age" : 18 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ad"), "ID" : 14, "name" : "jack14", "age" : 19 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ae"), "ID" : 15, "name" : "jack15", "age" : 20 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2af"), "ID" : 16, "name" : "jack16", "age" : 21 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b0"), "ID" : 17, "name" : "jack17", "age" : 22 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b1"), "ID" : 18, "name" : "jack18", "age" : 23 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b2"), "ID" : 19, "name" : "jack19", "age" : 24 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b3"), "ID" : 20, "name" : "jack20", "age" : 25 }
>                                 

14，查询指定列（name）数据

> db.user.find({},{"name":1})
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a0"), "name" : "jack1" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a1"), "name" : "jack2" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a2"), "name" : "jack3" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a3"), "name" : "jack4" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a4"), "name" : "jack5" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a5"), "name" : "jack6" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a6"), "name" : "jack7" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a7"), "name" : "jack8" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a8"), "name" : "jack9" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a9"), "name" : "jack10" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2aa"), "name" : "jack11" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ab"), "name" : "jack12" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ac"), "name" : "jack13" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ad"), "name" : "jack14" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ae"), "name" : "jack15" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2af"), "name" : "jack16" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b0"), "name" : "jack17" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b1"), "name" : "jack18" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b2"), "name" : "jack19" }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b3"), "name" : "jack20" }
>                    

15，查询指定列（naem，age>18）的数据：

> db.user.find({"age":{$gt:18}},{"name":1,"age":1})
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ad"), "name" : "jack14", "age" : 19 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ae"), "name" : "jack15", "age" : 20 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2af"), "name" : "jack16", "age" : 21 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b0"), "name" : "jack17", "age" : 22 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b1"), "name" : "jack18", "age" : 23 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b2"), "name" : "jack19", "age" : 24 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b3"), "name" : "jack20", "age" : 25 }
>                 

16，按照年龄排序（1 升序，-1 降序）

> db.user.find().sort({"age":1})
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a0"), "ID" : 1, "name" : "jack1", "age" : 6 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a1"), "ID" : 2, "name" : "jack2", "age" : 7 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a2"), "ID" : 3, "name" : "jack3", "age" : 8 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a3"), "ID" : 4, "name" : "jack4", "age" : 9 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a4"), "ID" : 5, "name" : "jack5", "age" : 10 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a5"), "ID" : 6, "name" : "jack6", "age" : 11 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a6"), "ID" : 7, "name" : "jack7", "age" : 12 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a7"), "ID" : 8, "name" : "jack8", "age" : 13 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a8"), "ID" : 9, "name" : "jack9", "age" : 14 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a9"), "ID" : 10, "name" : "jack10", "age" : 15 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2aa"), "ID" : 11, "name" : "jack11", "age" : 16 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ab"), "ID" : 12, "name" : "jack12", "age" : 17 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ac"), "ID" : 13, "name" : "jack13", "age" : 18 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ad"), "ID" : 14, "name" : "jack14", "age" : 19 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ae"), "ID" : 15, "name" : "jack15", "age" : 20 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2af"), "ID" : 16, "name" : "jack16", "age" : 21 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b0"), "ID" : 17, "name" : "jack17", "age" : 22 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b1"), "ID" : 18, "name" : "jack18", "age" : 23 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b2"), "ID" : 19, "name" : "jack19", "age" : 24 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b3"), "ID" : 20, "name" : "jack20", "age" : 25 }
>                            

降序：

> db.user.find().sort({"age":-1})
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b3"), "ID" : 20, "name" : "jack20", "age" : 25 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b2"), "ID" : 19, "name" : "jack19", "age" : 24 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b1"), "ID" : 18, "name" : "jack18", "age" : 23 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b0"), "ID" : 17, "name" : "jack17", "age" : 22 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2af"), "ID" : 16, "name" : "jack16", "age" : 21 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ae"), "ID" : 15, "name" : "jack15", "age" : 20 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ad"), "ID" : 14, "name" : "jack14", "age" : 19 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ac"), "ID" : 13, "name" : "jack13", "age" : 18 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ab"), "ID" : 12, "name" : "jack12", "age" : 17 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2aa"), "ID" : 11, "name" : "jack11", "age" : 16 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a9"), "ID" : 10, "name" : "jack10", "age" : 15 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a8"), "ID" : 9, "name" : "jack9", "age" : 14 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a7"), "ID" : 8, "name" : "jack8", "age" : 13 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a6"), "ID" : 7, "name" : "jack7", "age" : 12 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a5"), "ID" : 6, "name" : "jack6", "age" : 11 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a4"), "ID" : 5, "name" : "jack5", "age" : 10 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a3"), "ID" : 4, "name" : "jack4", "age" : 9 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a2"), "ID" : 3, "name" : "jack3", "age" : 8 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a1"), "ID" : 2, "name" : "jack2", "age" : 7 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a0"), "ID" : 1, "name" : "jack1", "age" : 6 }
>                           

17，查询前5条数据：

> db.user.find().limit(5)
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a0"), "ID" : 1, "name" : "jack1", "age" : 6 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a1"), "ID" : 2, "name" : "jack2", "age" : 7 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a2"), "ID" : 3, "name" : "jack3", "age" : 8 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a3"), "ID" : 4, "name" : "jack4", "age" : 9 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a4"), "ID" : 5, "name" : "jack5", "age" : 10 }
>

18，查询 10 条以后的数据：

> db.user.find().skip(10)
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2aa"), "ID" : 11, "name" : "jack11", "age" : 16 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ab"), "ID" : 12, "name" : "jack12", "age" : 17 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ac"), "ID" : 13, "name" : "jack13", "age" : 18 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ad"), "ID" : 14, "name" : "jack14", "age" : 19 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ae"), "ID" : 15, "name" : "jack15", "age" : 20 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2af"), "ID" : 16, "name" : "jack16", "age" : 21 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b0"), "ID" : 17, "name" : "jack17", "age" : 22 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b1"), "ID" : 18, "name" : "jack18", "age" : 23 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b2"), "ID" : 19, "name" : "jack19", "age" : 24 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2b3"), "ID" : 20, "name" : "jack20", "age" : 25 }
>

19，查询第6条到第15条数据（共10条）：

> db.user.find().limit(10).skip(5)
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a5"), "ID" : 6, "name" : "jack6", "age" : 11 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a6"), "ID" : 7, "name" : "jack7", "age" : 12 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a7"), "ID" : 8, "name" : "jack8", "age" : 13 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a8"), "ID" : 9, "name" : "jack9", "age" : 14 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a9"), "ID" : 10, "name" : "jack10", "age" : 15 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2aa"), "ID" : 11, "name" : "jack11", "age" : 16 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ab"), "ID" : 12, "name" : "jack12", "age" : 17 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ac"), "ID" : 13, "name" : "jack13", "age" : 18 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ad"), "ID" : 14, "name" : "jack14", "age" : 19 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ae"), "ID" : 15, "name" : "jack15", "age" : 20 }
>

20，or 查询：

> db.user.find({$or:[{age:18},{age:20}]})
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ac"), "ID" : 13, "name" : "jack13", "age" : 18 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ae"), "ID" : 15, "name" : "jack15", "age" : 20 }
>

21，findOne 查询第一条数据：

> db.user.findOne()
{
        "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a0"),
        "ID" : 1,
        "name" : "jack1",
        "age" : 6
}
>

22，查询某个结果集的记录条数，统计数量：

> db.user.find({age:{$gte:20}}).count()
6
> db.user.find({age:{$lte:20}}).count()
15
>

如果要返回限制之后的记录数量，要使用 count( true ) 或者 count(非0)

> db.user.find().skip(10).limit(5).count(true)
5
>

23，修改数据：查找名字叫做 jack13 的，把其年龄改为60

> db.user.update({"name":"jack13"},{$set:{"age":60}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.user.find({"name":jack13})
2020-06-18T20:58:09.541+0800 E QUERY    [js] ReferenceError: jack13 is not defined :
@(shell):1:15
> db.user.find({"name":"jack13"})
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ac"), "ID" : 13, "name" : "jack13", "age" : 60 }
>

没有写 $set ，会执行替换操作：

> db.user.update({"name":"jack13"},{"age":60})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.user.find({"name":"jack13"})
> db.user.find({"ID":13})
> db.user.find({"age":60})
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ac"), "age" : 60 }
>

24，把所有名字以 2结尾 的，都改为 tom：

> db.user.update({"name":/2$/},{$set:{"name":"tom"}},{multi:true})
WriteResult({ "nMatched" : 2, "nUpserted" : 0, "nModified" : 2 })
> db.user.find({"name":/2$/})
> db.user.find({"name":"tom"})
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2a1"), "ID" : 2, "name" : "tom", "age" : 7 }
{ "_id" : ObjectId("5eeb59f89b5a0b09e5f8c2ab"), "ID" : 12, "name" : "tom", "age" : 17 }
>

25，删除当前所在的数据库：

db.dropDatabase( )

26，删除数据：

> db.user.insert({"ID":21,"name":"jack21",age:26})
WriteResult({ "nInserted" : 1 })
> db.user.find("name":"jack21")
2020-06-18T21:12:04.405+0800 E QUERY    [js] SyntaxError: missing ) after argument list @(shell):1:19
> db.user.find({"name":"jack21"})
{ "_id" : ObjectId("5eeb680e9b5a0b09e5f8c2b4"), "ID" : 21, "name" : "jack21", "age" : 26 }
> db.user.remove({"name":"jack21"})
WriteResult({ "nRemoved" : 1 })
> db.user.find({"name":"jack21"})
>