MongoDB-2-命令

柔光的暖阳◎ 2022-02-19 02:21 210阅读 0赞

## MongoDB-2-命令 ##

show dbs;–查看所有库

use 库名;–创建库,没有该库就创建库,有就切换为该库

db;–查看当前使用的库

db.dropDatabase();–删除当前库

db.createCollection(name, options);–创建集合  
name: 要创建的集合名称  
options: 可选参数, 指定有关内存大小及索引的选项  
参数说明:  
options 可以是如下参数：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDkxNDc4NA_size_16_color_FFFFFF_t_70]  
show collections;–查看都有哪些集合  
show tables;–查看都有哪些集合  
db.getCollectionInfos();–查看都有哪些集合

db.集合名.drop();–删除指定集合

db.集合名.insert(document);–向集合中插入文档,文档需要是json格式,如db.user.insert(\{“name”:“Gqc”\});

db.集合名.find(query);–条件查询  
db.集合名.find(query).pretty();–格式化查询  
db.集合名.find(query).count();–查询有多少条数据

db.集合名.update(  
,  
,  
\{  
upsert: ,  
multi:  
\}  
)  
参数说明：  
query : update的查询条件，类似sql update查询内where后面的。  
update : update的对象和一些更新的操作符（如 , , ,set…）等，也可以理解为sql update查询内set后面的  
upsert : 可选，这个参数的意思是，如果不存在update的记录，是否插入该数据,true为插入，默认是false，不插入。  
multi : 可选，mongodb 默认是false,只更新找到的第一条记录，如果这个参数为true,就把按条件查出来多条记录全部更新。  
例:  
db.student.update(\{“name”:“gqc”\},\{“age”:“18”\});–将名为gqc的第一条数据年龄改为18,注意:原有数据中其他列的值都会改为空  
db.student.update(\{“name”:“gqc”\},\{ KaTeX parse error: Expected 'EOF', got '\}' at position 17: …et:\{"age":"18"\}\}̲);--将名为gqc的第一条数…set:\{“age”:“18”\}\},\{upsert:true\});–更改名为gqc的数据,如果没有则新增  
db.student.update(\{“name”:“gqc”\},\{$set:\{“age”:“18”\}\},\{multi:true\});–将名为gqc的所有数据都更改

db.集合名.remove(  
,  
  
)  
参数说明：  
query :（可选）删除的文档的条件。  
justOne : （可选）如果设为 true 或 1，则只删除一个文档。  
db.集合名.remove(\{\});–删除所有数据

## MongoDB 与 RDBMS Where 语句比较 ##

如果你熟悉常规的 SQL 数据，通过下表可以更好的理解 MongoDB 的条件语句查询：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDkxNDc4NA_size_16_color_FFFFFF_t_70 1]  
db.集合名.find(\{key1:value1, key2:value2\}).pretty();–多个条件的And查询  
例:db.user.find(\{“name”:“gqc”,“age”:18\});–类似于where name=‘gqc’ and age=18  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDkxNDc4NA_size_16_color_FFFFFF_t_70 2]

and和or连用,例:  
db.col.find(\{“age”: \{$gt:20\}, $or: \[\{“name”: “xk”\},\{“sex”: 1\}\]\}).pretty();–类似于where age>20 and(name=‘xk’ or sex=1)

db.集合名.find().skip(开始坐标).limit(显示条数);–分页查询,开始坐标的公式应为(页数-1)\*条数

db.集合名.find().sort(\{排序列:排序方式\});–将集合排序,排序方式1为升序,-1为降序

日期使用:  
new Date();–当前时间  
ISODate();–当前时间  
注:new Date();和ISODate();获得的当前时间是格林尼治时间,与我们相差8小时  
Date();–获得当前时间

## 下面是我敲的一些命令 ##

MongoDB shell version v3.4.6
    connecting to: mongodb://127.0.0.1:27017
    MongoDB server version: 3.4.6
    Server has startup warnings:
    2019-04-10T13:38:45.522+0800 I CONTROL  [initandlisten]
    2019-04-10T13:38:45.523+0800 I CONTROL  [initandlisten] ** WARNING: Access control is not enabled for the database.
    2019-04-10T13:38:45.523+0800 I CONTROL  [initandlisten] **          Read and write access to data and configuration is unrestricted.
    2019-04-10T13:38:45.523+0800 I CONTROL  [initandlisten]
    > show dbs
    admin  0.000GB
    local  0.000GB
    > show dbs
    admin  0.000GB
    local  0.000GB
    > use mr
    switched to db mr
    > db;
    mr
    > use admin
    switched to db admin
    > db;
    admin
    > use mr
    switched to db mr
    > db;
    mr
    > db.dropDatabase();
    { "ok" : 1 }
    > db
    mr
    > show dbs;
    admin  0.000GB
    local  0.000GB
    > use admin;
    switched to db admin
    > db;
    admin
    > db.createCollection("user";)
    2019-04-10T13:55:08.121+0800 E QUERY    [thread1] SyntaxError: missing ) after argument list @(shell):1:26
    > db.createCollection("user");
    { "ok" : 1 }
    > show dbs;
    admin  0.000GB
    local  0.000GB
    > use mr;
    switched to db mr
    > dbs;
    2019-04-10T13:56:39.910+0800 E QUERY    [thread1] ReferenceError: dbs is not defined :
    @(shell):1:1
    > db;
    mr
    > db.createCollection("user");
    { "ok" : 1 }
    > show dbs;
    admin  0.000GB
    local  0.000GB
    mr     0.000GB
    > show collections;
    user
    > show tables;
    user
    > db.getCollectionInfos();
    [
            {
                    "name" : "user",
                    "type" : "collection",
                    "options" : {
    
                    },
                    "info" : {
                            "readOnly" : false
                    },
                    "idIndex" : {
                            "v" : 2,
                            "key" : {
                                    "_id" : 1
                            },
                            "name" : "_id_",
                            "ns" : "mr.user"
                    }
            }
    ]
    > db.user.insert({"name":"yuanbo"});
    WriteResult({ "nInserted" : 1 })
    > db.getCollectionInfos();
    [
            {
                    "name" : "user",
                    "type" : "collection",
                    "options" : {
    
                    },
                    "info" : {
                            "readOnly" : false
                    },
                    "idIndex" : {
                            "v" : 2,
                            "key" : {
                                    "_id" : 1
                            },
                            "name" : "_id_",
                            "ns" : "mr.user"
                    }
            }
    ]
    > db.createCollection("stu",<max:2000>);
    2019-04-10T14:07:08.694+0800 E QUERY    [thread1] SyntaxError: expected expression, got '<' @(shell):1:26
    > db.createCollection("stu",(max:2000));
    2019-04-10T14:07:38.645+0800 E QUERY    [thread1] SyntaxError: missing ) in parenthetical @(shell):1:30
    > db.createCollection("stu",(max:2000))
    2019-04-10T14:09:18.940+0800 E QUERY    [thread1] SyntaxError: missing ) in parenthetical @(shell):1:30
    > db.createCollection("stu",(max:2000))
    2019-04-10T14:09:47.881+0800 E QUERY    [thread1] SyntaxError: missing ) in parenthetical @(shell):1:30
    > show dbs;
    admin  0.000GB
    local  0.000GB
    mr     0.000GB
    > use user;
    switched to db user
    > db;
    user
    > show collections;
    > show collections;
    > db.createCollections("student",(max:1000))
    2019-04-10T14:13:34.008+0800 E QUERY    [thread1] SyntaxError: missing ) in parenthetical @(shell):1:35
    > show tables;
    > show dbs;
    admin  0.000GB
    local  0.000GB
    mr     0.000GB
    > use mr;
    switched to db mr
    > db;
    mr
    > db.createCollection("stu");
    { "ok" : 1 }
    > show collections;
    stu
    user
    > show tables;
    stu
    user
    > db.user.drop();
    true
    > show collections;
    stu
    > db.stu.drop();
    true
    > show tables;
    > db.user.insert({"name":"yuanbo"})
    WriteResult({ "nInserted" : 1 })
    > db.user.insert((name:"gqc",age:19))
    2019-04-10T14:23:42.793+0800 E QUERY    [thread1] SyntaxError: missing ) in parenthetical @(shell):1:20
    > db.user.insert((name:"gqc",age:19));
    2019-04-10T14:23:47.288+0800 E QUERY    [thread1] SyntaxError: missing ) in parenthetical @(shell):1:20
    > db.user.find()
    { "_id" : ObjectId("5cad8b9a291f5801b1f2040c"), "name" : "yuanbo" }
    > db.user.insert((name:"gqc",age:19));
    2019-04-10T14:25:51.100+0800 E QUERY    [thread1] SyntaxError: missing ) in parenthetical @(shell):1:20
    > db.user.insert(("name":"gqc","age":19));
    2019-04-10T14:28:23.123+0800 E QUERY    [thread1] SyntaxError: missing ) in parenthetical @(shell):1:22
    > db.user.insert(("name":"gqc","age":19))
    2019-04-10T14:28:34.136+0800 E QUERY    [thread1] SyntaxError: missing ) in parenthetical @(shell):1:22
    > db.user.insert({"name":"gqc","age":19})
    WriteResult({ "nInserted" : 1 })
    > db.user.find()
    { "_id" : ObjectId("5cad8b9a291f5801b1f2040c"), "name" : "yuanbo" }
    { "_id" : ObjectId("5cad8d4a291f5801b1f2040d"), "name" : "gqc", "age" : 19 }
    > show tables
    user
    > db.user.insert({"name":"yuanbo1","age":"19","sex":"男"})
    WriteResult({ "nInserted" : 1 })
    > db.user.find()
    { "_id" : ObjectId("5cad8b9a291f5801b1f2040c"), "name" : "yuanbo" }
    { "_id" : ObjectId("5cad8d4a291f5801b1f2040d"), "name" : "gqc", "age" : 19 }
    { "_id" : ObjectId("5cad8de2291f5801b1f2040e"), "name" : "yuanbo1", "age" : "19", "sex" : "男" }
    > db.user.find({"name":"yuanbo"})
    { "_id" : ObjectId("5cad8b9a291f5801b1f2040c"), "name" : "yuanbo" }
    > db.user.find().pretty()
    { "_id" : ObjectId("5cad8b9a291f5801b1f2040c"), "name" : "yuanbo" }
    { "_id" : ObjectId("5cad8d4a291f5801b1f2040d"), "name" : "gqc", "age" : 19 }
    {
            "_id" : ObjectId("5cad8de2291f5801b1f2040e"),
            "name" : "yuanbo1",
            "age" : "19",
            "sex" : "男"
    }
    > db.user.find().count()
    3
    > db.user.update({"name":"gqc"},{"name":"gqc1"})
    WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
    > db.user.find();
    { "_id" : ObjectId("5cad8b9a291f5801b1f2040c"), "name" : "yuanbo" }
    { "_id" : ObjectId("5cad8d4a291f5801b1f2040d"), "name" : "gqc1" }
    { "_id" : ObjectId("5cad8de2291f5801b1f2040e"), "name" : "yuanbo1", "age" : "19", "sex" : "男" }
    > db.user.update({"name":"gqc1"},{"name":"gqc","age":"35"})
    WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
    > db.user.find()
    { "_id" : ObjectId("5cad8b9a291f5801b1f2040c"), "name" : "yuanbo" }
    { "_id" : ObjectId("5cad8d4a291f5801b1f2040d"), "name" : "gqc", "age" : "35" }
    { "_id" : ObjectId("5cad8de2291f5801b1f2040e"), "name" : "yuanbo1", "age" : "19", "sex" : "男" }
    > db.user.update({"name":"gqc"},{$set:{"age":"30"}})
    WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
    > db.user.find()
    { "_id" : ObjectId("5cad8b9a291f5801b1f2040c"), "name" : "yuanbo" }
    { "_id" : ObjectId("5cad8d4a291f5801b1f2040d"), "name" : "gqc", "age" : "30" }
    { "_id" : ObjectId("5cad8de2291f5801b1f2040e"), "name" : "yuanbo1", "age" : "19", "sex" : "男" }
    > db.user.update({"name":"gqc1"},{$set:{"name":"gqc3"}},{upset:true})
    WriteResult({ "nMatched" : 0, "nUpserted" : 0, "nModified" : 0 })
    > db.user.find()
    { "_id" : ObjectId("5cad8b9a291f5801b1f2040c"), "name" : "yuanbo" }
    { "_id" : ObjectId("5cad8d4a291f5801b1f2040d"), "name" : "gqc", "age" : "30" }
    { "_id" : ObjectId("5cad8de2291f5801b1f2040e"), "name" : "yuanbo1", "age" : "19", "sex" : "男" }
    > db.user.update({"name":"gqc1"},{$set:{"name":"gqc3"}},{upsert:true})
    WriteResult({
            "nMatched" : 0,
            "nUpserted" : 1,
            "nModified" : 0,
            "_id" : ObjectId("5cad95749022790e68c02af1")
    })
    > db.user.find()
    { "_id" : ObjectId("5cad8b9a291f5801b1f2040c"), "name" : "yuanbo" }
    { "_id" : ObjectId("5cad8d4a291f5801b1f2040d"), "name" : "gqc", "age" : "30" }
    { "_id" : ObjectId("5cad8de2291f5801b1f2040e"), "name" : "yuanbo1", "age" : "19", "sex" : "男" }
    { "_id" : ObjectId("5cad95749022790e68c02af1"), "name" : "gqc3" }
    > db.user.update({"name":"gqc3"},{$set:{"name":"gqc4"}},{multi:true})
    WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
    > db.user.find()
    { "_id" : ObjectId("5cad8b9a291f5801b1f2040c"), "name" : "yuanbo" }
    { "_id" : ObjectId("5cad8d4a291f5801b1f2040d"), "name" : "gqc", "age" : "30" }
    { "_id" : ObjectId("5cad8de2291f5801b1f2040e"), "name" : "yuanbo1", "age" : "19", "sex" : "男" }
    { "_id" : ObjectId("5cad95749022790e68c02af1"), "name" : "gqc4" }
    > db.user.remove({"name":"gqc4"},{justOne})
    2019-04-10T15:11:02.636+0800 E QUERY    [thread1] ReferenceError: justOne is not defined :
    @(shell):1:33
    > db.user.remove({"name":"gqc4"},{justOne:true})
    WriteResult({ "nRemoved" : 1 })
    > db.user.find()
    { "_id" : ObjectId("5cad8b9a291f5801b1f2040c"), "name" : "yuanbo" }
    { "_id" : ObjectId("5cad8d4a291f5801b1f2040d"), "name" : "gqc", "age" : "30" }
    { "_id" : ObjectId("5cad8de2291f5801b1f2040e"), "name" : "yuanbo1", "age" : "19", "sex" : "男" }
    > db.user.find({age:{$lte:19}})
    > db.user.find({"age":{$lte:19}})
    > db.user.find({"age":{$lte:"19"}})
    { "_id" : ObjectId("5cad8de2291f5801b1f2040e"), "name" : "yuanbo1", "age" : "19", "sex" : "男" }
    > db.user.find({"name":"yuanbo1","age":"19"})
    { "_id" : ObjectId("5cad8de2291f5801b1f2040e"), "name" : "yuanbo1", "age" : "19", "sex" : "男" }
    > db.user.find({$or:[{"name":"yuanbo1"},{"name":"gqc"}]})
    { "_id" : ObjectId("5cad8d4a291f5801b1f2040d"), "name" : "gqc", "age" : "30" }
    { "_id" : ObjectId("5cad8de2291f5801b1f2040e"), "name" : "yuanbo1", "age" : "19", "sex" : "男" }
    > db.user.find({"age": {$gt:20}, $or: [{"name": "yuanbo"},{"sex":"男"}]}).pretty();
    > db.user.find({"age": {$gt:16}, $or: [{"name": "yuanbo"},{"sex":"男"}]}).pretty();
    > db.user.find({"age": {$gt:16}, $or: [{"name": "yuanbo"},{"sex":"男"}]}).pretty();
    > db.user.find({"age": {$gt:"6"}, $or: [{"name": "yuanbo"},{"sex":"男"}]}).pretty())
    > db.user.find({"age": {$gt:"6"}, $or: [{"name": "yuanbo"},{"sex":"男"}]}).pretty()
    > db.user.find({"age": {$gt:"6"}, $or: [{"name": "yuanbo1"},{"sex":"男"}]}).pretty()
    > db.user.find({"age": {$gt:"6"}, $or: [{"name": "yuanbo"},{"sex":"男"}]}).pretty())
    > new Date()
    ISODate("2019-04-10T07:36:33.912Z")
    > ISODate()
    ISODate("2019-04-10T07:36:49.396Z")
    > Date()
    Wed Apr 10 2019 15:36:59 GMT+0800
    > db.user.remove({"name":"gqc4"},{justOne:true})

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDkxNDc4NA_size_16_color_FFFFFF_t_70]: /images/20220219/33ed3a910ef74c7a841cb7b032fe529e.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDkxNDc4NA_size_16_color_FFFFFF_t_70 1]: /images/20220219/d17ca433be63422980e39fedf3f682d9.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDkxNDc4NA_size_16_color_FFFFFF_t_70 2]: /images/20220219/738c7d786f444452a3d06100fe96b32a.png