mongodb-基础-update-remove

小鱼儿 2022-07-16 07:40 90阅读 0赞

**1.一些操作**

collection重命名：

> db.post.renameCollection('foo')
    { "ok" : 1 }
    > show collections
    foo

**2.update**

** **

**语法格式：**

db.collection.update(
      <query>,
      <update>,
      {
        upsert: <boolean>,
        multi: <boolean>,
        writeConcern: <document>
      })

**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$,$inc...）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objNew,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。
 *  **writeConcern **:可选，抛出异常的级别。

** **

**示例：**

>db.foo.insert([
         {"title":"MongoDB Overview"},
         {"title":"NoSQL Overview"},
         {"title":"Test Update"}
    ])
    
    > db.foo.find()
    { "_id" : ObjectId("577f11860fe1ae602eda933a"), "title" : "MongoDB Overview" }
    { "_id" : ObjectId("577f11860fe1ae602eda933b"), "title" : "NoSQL Overview" }
    { "_id" : ObjectId("577f11860fe1ae602eda933c"), "title" : "Test Update" }
    >
    > db.foo.update(
    ... {'title':'MongoDB Overview'},
    ... {$set:{'title':'New MongoDB Overview'}}
    ... )
    WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
    >
    > db.foo.find()
    { "_id" : ObjectId("577f11860fe1ae602eda933a"), "title" : "New MongoDB Overview"
     }
    { "_id" : ObjectId("577f11860fe1ae602eda933b"), "title" : "NoSQL Overview" }
    { "_id" : ObjectId("577f11860fe1ae602eda933c"), "title" : "Test Update" }
    >

**测试更新多个：**

# 初始化数据
    > db.post.insert(
    [
    {'username':'Ryan','age':18,'sex':0,'hobby':'read'},
    {'username':'Leslie','age':18,'sex':1,'hobby':'watch TV'},
    {'username':'Tom','age':20,'sex':0,'hobby':'eat 老鼠'}
    ])
    BulkWriteResult({
            "writeErrors" : [ ],
            "writeConcernErrors" : [ ],
            "nInserted" : 3,
            "nUpserted" : 0,
            "nMatched" : 0,
            "nModified" : 0,
            "nRemoved" : 0,
            "upserted" : [ ]
    })
    
    > db.post.find().pretty()
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933d"),
            "username" : "Ryan",
            "age" : 18,
            "sex" : 0,
            "hobby" : "read"
    }
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933e"),
            "username" : "Leslie",
            "age" : 18,
            "sex" : 1,
            "hobby" : "watch TV"
    }
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933f"),
            "username" : "Tom",
            "age" : 20,
            "sex" : 0,
            "hobby" : "eat 老鼠"
    }

**结果发现，这种更新只能更新匹配的第一条记录：**

#更新age=18的为age=20
    > db.post.update(
    ... {'age':18},
    ... {$set:{'age':20}}
    ... )
    WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
    > db.post.find().pretty()
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933d"),
            "username" : "Ryan",
            "age" : 20,
            "sex" : 0,
            "hobby" : "read"
    }
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933e"),
            "username" : "Leslie",
            "age" : 18,
            "sex" : 1,
            "hobby" : "watch TV"
    }
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933f"),
            "username" : "Tom",
            "age" : 20,
            "sex" : 0,
            "hobby" : "eat 老鼠"
    }

如果想要更新符合条件的所有的记录，需要设置multi:true:

# 更新age=20 为 age=22
    > db.post.update( {'age':20}, {$set:{'age':22}},{multi:true} )
    WriteResult({ "nMatched" : 2, "nUpserted" : 0, "nModified" : 2 })
    > db.post.find().pretty()
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933d"),
            "username" : "Ryan",
            "age" : 22,
            "sex" : 0,
            "hobby" : "read"
    }
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933e"),
            "username" : "Leslie",
            "age" : 18,
            "sex" : 1,
            "hobby" : "watch TV"
    }
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933f"),
            "username" : "Tom",
            "age" : 22,
            "sex" : 0,
            "hobby" : "eat 老鼠"
    }

## 3.save() 方法 ##

save() 方法通过传入的文档来替换已有文档。语法格式如下：

db.collection.save(<document>,{
          
         writeConcern:<document>})

**参数说明：**

*  **document **: 文档数据。
 *  **writeConcern **:可选，抛出异常的级别

如果传入的文档中含有\_id，并且\_id的值是数据库中已经存在的，则替换该条记录。

如果传入的文档中含有\_id，并且\_id的值在数据库中不存在，则相当于insert，插入一条数据。

如果传入的文档中没有\_id，则相当于insert，插入一条数据。

**示例：**

数据库中元数据：

> db.post.find().pretty()
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933d"),
            "username" : "Ryan",
            "age" : 22,
            "sex" : 0,
            "hobby" : "read"
    }
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933e"),
            "username" : "Leslie",
            "age" : 18,
            "sex" : 1,
            "hobby" : "watch TV"
    }
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933f"),
            "username" : "Tom",
            "age" : 22,
            "sex" : 0,
            "hobby" : "eat 老鼠"
    }

替换最后一条记录：

> db.post.save({
    ... "_id" : ObjectId("577f145a0fe1ae602eda933f"),
    ... "username":"Jack",
    ... "age":30,
    ... sex:1,
    ... hobby:'running'
    ... })
    WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
    > db.post.find().pretty()
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933d"),
            "username" : "Ryan",
            "age" : 22,
            "sex" : 0,
            "hobby" : "read"
    }
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933e"),
            "username" : "Leslie",
            "age" : 18,
            "sex" : 1,
            "hobby" : "watch TV"
    }
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933f"),
            "username" : "Jack",
            "age" : 30,
            "sex" : 1,
            "hobby" : "running"
    }

如果没有指定\_id，相当于insert：

> db.post.save({ "username":"Mary", "age":28, sex:0, hobby:'sleep' })
    WriteResult({ "nInserted" : 1 })
    > db.post.find().pretty()
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933d"),
            "username" : "Ryan",
            "age" : 22,
            "sex" : 0,
            "hobby" : "read"
    }
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933e"),
            "username" : "Leslie",
            "age" : 18,
            "sex" : 1,
            "hobby" : "watch TV"
    }
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933f"),
            "username" : "Jack",
            "age" : 30,
            "sex" : 1,
            "hobby" : "running"
    }
    {
            "_id" : ObjectId("577f1fd30fe1ae602eda9340"),
            "username" : "Mary",
            "age" : 28,
            "sex" : 0,
            "hobby" : "sleep"
    }

如果指定了\_id,但没有数据库匹配该id，则相当于insert，插入一条数据：

> db.post.save({ "_id" : 123123, "username":"Jack", "age":30, sex:1, hobby:'runn
    ing' })
    WriteResult({ "nMatched" : 0, "nUpserted" : 1, "nModified" : 0, "_id" : 123123 }
    )
    > db.post.find().pretty()
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933d"),
            "username" : "Ryan",
            "age" : 22,
            "sex" : 0,
            "hobby" : "read"
    }
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933e"),
            "username" : "Leslie",
            "age" : 18,
            "sex" : 1,
            "hobby" : "watch TV"
    }
    {
            "_id" : ObjectId("577f145a0fe1ae602eda933f"),
            "username" : "Jack",
            "age" : 30,
            "sex" : 1,
            "hobby" : "running"
    }
    {
            "_id" : ObjectId("577f1fd30fe1ae602eda9340"),
            "username" : "Mary",
            "age" : 28,
            "sex" : 0,
            "hobby" : "sleep"
    }
    {
            "_id" : 123123,
            "username" : "Jack",
            "age" : 30,
            "sex" : 1,
            "hobby" : "running"
    }

## 更多实例 ##

只更新第一条记录：

db.col.update( \{ "count" : \{ $gt : 1 \} \} , \{ $set : \{ "test2" : "OK"\} \} );

全部更新：

db.col.update( \{ "count" : \{ $gt : 3 \} \} , \{ $set : \{ "test2" : "OK"\} \},false,true );

只添加第一条：

db.col.update( \{ "count" : \{ $gt : 4 \} \} , \{ $set : \{ "test5" : "OK"\} \},true,false );

全部添加加进去:

db.col.update( \{ "count" : \{ $gt : 5 \} \} , \{ $set : \{ "test5" : "OK"\} \},true,true );

全部更新：

db.col.update( \{ "count" : \{ $gt : 15 \} \} , \{ $inc : \{ "count" : 1\} \},false,true );

只更新第一条记录：

db.col.update( \{ "count" : \{ $gt : 10 \} \} , \{ $inc : \{ "count" : 1\} \},false,false );

**4.remove**

### 语法 ###

remove() 方法的基本语法格式如下所示：

db.collection.remove(<query>,<justOne>)

如果你的 MongoDB 是 2.6 版本以后的，语法格式如下：

db.collection.remove(<query>,{
           
         justOne:<boolean>,
         writeConcern:<document>})

**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。
 *  **writeConcern **:（可选）抛出异常的级别。

**示例：**

首先插入两条数据：

> db.col.insert({
    ... title:'MongoDB Teach',
    ... by:'菜鸟教程',
    ... url:'http://www.runoob.com',
    ... tags:['mongodb','database','NoSQL'],
    ... likes:100
    ... })
    WriteResult({ "nInserted" : 1 })
    > db.col.insert({ title:'MongoDB Teach', by:'菜鸟教程', url:'http://www.runoob.c
    om', tags:['mongodb','database','NoSQL'], likes:100 })
    WriteResult({ "nInserted" : 1 })
    >
    >
    > db.col.find()
    { "_id" : ObjectId("577f52430fe1ae602eda9341"), "title" : "MongoDB Teach", "by"
    : "菜鸟教程", "url" : "http://www.runoob.com", "tags" : [ "mongodb", "database",
     "NoSQL" ], "likes" : 100 }
    { "_id" : ObjectId("577f52460fe1ae602eda9342"), "title" : "MongoDB Teach", "by"
    : "菜鸟教程", "url" : "http://www.runoob.com", "tags" : [ "mongodb", "database",
     "NoSQL" ], "likes" : 100 }

然后，删除：

> db.col.remove({'title':'MongoDB Teach'})
    WriteResult({ "nRemoved" : 2 })

可以看到，两条都删除了，即：满足条件的都删除。因此，如果想清空表：

> db.col.remove({})

相当于 SQL 的 truncate 命令.

**1.一些操作**

collection重命名：

> db.post.renameCollection('foo')

\{ "ok" : 1 \}

> show collections

foo

**2.update**

** **

**语法格式：**

db.collection.update(  
  <query>,  
  <update>,  
  \{  
    upsert: <boolean>,  
    multi: <boolean>,  
    writeConcern: <document>  
  \})

**参数说明：**

** **

**示例：**

>db.foo.insert(\[

\{"title":"MongoDB Overview"\},

\{"title":"NoSQL Overview"\},

\{"title":"Test Update"\}

\])

> db.foo.find()

\{ "\_id" : ObjectId("577f11860fe1ae602eda933a"), "title" : "MongoDB Overview" \}

\{ "\_id" : ObjectId("577f11860fe1ae602eda933b"), "title" : "NoSQL Overview" \}

\{ "\_id" : ObjectId("577f11860fe1ae602eda933c"), "title" : "Test Update" \}

> db.foo.update(

... \{'title':'MongoDB Overview'\},

... \{$set:\{'title':'New MongoDB Overview'\}\}

... )

WriteResult(\{ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 \})

> db.foo.find()

\{ "\_id" : ObjectId("577f11860fe1ae602eda933a"), "title" : "New MongoDB Overview"

\{ "\_id" : ObjectId("577f11860fe1ae602eda933b"), "title" : "NoSQL Overview" \}

\{ "\_id" : ObjectId("577f11860fe1ae602eda933c"), "title" : "Test Update" \}

**测试更新多个：**

\# 初始化数据

> db.post.insert(

\{'username':'Ryan','age':18,'sex':0,'hobby':'read'\},

\{'username':'Leslie','age':18,'sex':1,'hobby':'watch TV'\},

\{'username':'Tom','age':20,'sex':0,'hobby':'eat 老鼠'\}

\])

BulkWriteResult(\{

"writeErrors" : \[ \],

"writeConcernErrors" : \[ \],

"nInserted" : 3,

"nUpserted" : 0,

"nMatched" : 0,

"nModified" : 0,

"nRemoved" : 0,

"upserted" : \[ \]

\})

> db.post.find().pretty()

"\_id" : ObjectId("577f145a0fe1ae602eda933d"),

"username" : "Ryan",

"age" : 18,

"sex" : 0,

"hobby" : "read"

"\_id" : ObjectId("577f145a0fe1ae602eda933e"),

"username" : "Leslie",

"age" : 18,

"sex" : 1,

"hobby" : "watch TV"

"\_id" : ObjectId("577f145a0fe1ae602eda933f"),

"username" : "Tom",

"age" : 20,

"sex" : 0,

"hobby" : "eat 老鼠"

**结果发现，这种更新只能更新匹配的第一条记录：**

\#更新age=18的为age=20

> db.post.update(

... \{'age':18\},

... \{$set:\{'age':20\}\}

... )

WriteResult(\{ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 \})

> db.post.find().pretty()

"\_id" : ObjectId("577f145a0fe1ae602eda933d"),

"username" : "Ryan",

"age" : 20,

"sex" : 0,

"hobby" : "read"

"\_id" : ObjectId("577f145a0fe1ae602eda933e"),

"username" : "Leslie",

"age" : 18,

"sex" : 1,

"hobby" : "watch TV"

"\_id" : ObjectId("577f145a0fe1ae602eda933f"),

"username" : "Tom",

"age" : 20,

"sex" : 0,

"hobby" : "eat 老鼠"

如果想要更新符合条件的所有的记录，需要设置multi:true:

\# 更新age=20 为 age=22

> db.post.update( \{'age':20\}, \{$set:\{'age':22\}\},\{multi:true\} )

WriteResult(\{ "nMatched" : 2, "nUpserted" : 0, "nModified" : 2 \})

> db.post.find().pretty()

"\_id" : ObjectId("577f145a0fe1ae602eda933d"),

"username" : "Ryan",

"age" : 22,

"sex" : 0,

"hobby" : "read"

"\_id" : ObjectId("577f145a0fe1ae602eda933e"),

"username" : "Leslie",

"age" : 18,

"sex" : 1,

"hobby" : "watch TV"

"\_id" : ObjectId("577f145a0fe1ae602eda933f"),

"username" : "Tom",

"age" : 22,

"sex" : 0,

"hobby" : "eat 老鼠"

## 3.save() 方法 ##

save() 方法通过传入的文档来替换已有文档。语法格式如下：

db.collection.save(<document>,{
        
         writeConcern:<document>})

**参数说明：**

*  **document **: 文档数据。
 *  **writeConcern **:可选，抛出异常的级别

如果传入的文档中含有\_id，并且\_id的值是数据库中已经存在的，则替换该条记录。

如果传入的文档中含有\_id，并且\_id的值在数据库中不存在，则相当于insert，插入一条数据。

如果传入的文档中没有\_id，则相当于insert，插入一条数据。

**示例：**

数据库中元数据：

> db.post.find().pretty()

"\_id" : ObjectId("577f145a0fe1ae602eda933d"),

"username" : "Ryan",

"age" : 22,

"sex" : 0,

"hobby" : "read"

"\_id" : ObjectId("577f145a0fe1ae602eda933e"),

"username" : "Leslie",

"age" : 18,

"sex" : 1,

"hobby" : "watch TV"

"\_id" : ObjectId("577f145a0fe1ae602eda933f"),

"username" : "Tom",

"age" : 22,

"sex" : 0,

"hobby" : "eat 老鼠"

替换最后一条记录：

> db.post.save(\{

... "\_id" : ObjectId("577f145a0fe1ae602eda933f"),

... "username":"Jack",

... "age":30,

... sex:1,

... hobby:'running'

... \})

WriteResult(\{ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 \})

> db.post.find().pretty()

"\_id" : ObjectId("577f145a0fe1ae602eda933d"),

"username" : "Ryan",

"age" : 22,

"sex" : 0,

"hobby" : "read"

"\_id" : ObjectId("577f145a0fe1ae602eda933e"),

"username" : "Leslie",

"age" : 18,

"sex" : 1,

"hobby" : "watch TV"

"\_id" : ObjectId("577f145a0fe1ae602eda933f"),

"username" : "Jack",

"age" : 30,

"sex" : 1,

"hobby" : "running"

如果没有指定\_id，相当于insert：

> db.post.save(\{ "username":"Mary", "age":28, sex:0, hobby:'sleep' \})

WriteResult(\{ "nInserted" : 1 \})

> db.post.find().pretty()

"\_id" : ObjectId("577f145a0fe1ae602eda933d"),

"username" : "Ryan",

"age" : 22,

"sex" : 0,

"hobby" : "read"

"\_id" : ObjectId("577f145a0fe1ae602eda933e"),

"username" : "Leslie",

"age" : 18,

"sex" : 1,

"hobby" : "watch TV"

"\_id" : ObjectId("577f145a0fe1ae602eda933f"),

"username" : "Jack",

"age" : 30,

"sex" : 1,

"hobby" : "running"

"\_id" : ObjectId("577f1fd30fe1ae602eda9340"),

"username" : "Mary",

"age" : 28,

"sex" : 0,

"hobby" : "sleep"

如果指定了\_id,但没有数据库匹配该id，则相当于insert，插入一条数据：

> db.post.save(\{ "\_id" : 123123, "username":"Jack", "age":30, sex:1, hobby:'runn

ing' \})

WriteResult(\{ "nMatched" : 0, "nUpserted" : 1, "nModified" : 0, "\_id" : 123123 \}

)

> db.post.find().pretty()

"\_id" : ObjectId("577f145a0fe1ae602eda933d"),

"username" : "Ryan",

"age" : 22,

"sex" : 0,

"hobby" : "read"

"\_id" : ObjectId("577f145a0fe1ae602eda933e"),

"username" : "Leslie",

"age" : 18,

"sex" : 1,

"hobby" : "watch TV"

"\_id" : ObjectId("577f145a0fe1ae602eda933f"),

"username" : "Jack",

"age" : 30,

"sex" : 1,

"hobby" : "running"

"\_id" : ObjectId("577f1fd30fe1ae602eda9340"),

"username" : "Mary",

"age" : 28,

"sex" : 0,

"hobby" : "sleep"

"\_id" : 123123,

"username" : "Jack",

"age" : 30,

"sex" : 1,

"hobby" : "running"

## 更多实例 ##

只更新第一条记录：

db.col.update( \{ "count" : \{ $gt : 1 \} \} , \{ $set : \{ "test2" : "OK"\} \} );

全部更新：

db.col.update( \{ "count" : \{ $gt : 3 \} \} , \{ $set : \{ "test2" : "OK"\} \},false,true );

只添加第一条：

db.col.update( \{ "count" : \{ $gt : 4 \} \} , \{ $set : \{ "test5" : "OK"\} \},true,false );

全部添加加进去:

db.col.update( \{ "count" : \{ $gt : 5 \} \} , \{ $set : \{ "test5" : "OK"\} \},true,true );

全部更新：

db.col.update( \{ "count" : \{ $gt : 15 \} \} , \{ $inc : \{ "count" : 1\} \},false,true );

只更新第一条记录：

db.col.update( \{ "count" : \{ $gt : 10 \} \} , \{ $inc : \{ "count" : 1\} \},false,false );

**4.remove**

### 语法 ###

remove() 方法的基本语法格式如下所示：

db.collection.remove(<query>,<justOne>)

如果你的 MongoDB 是 2.6 版本以后的，语法格式如下：

db.collection.remove(<query>,{
        
         justOne:<boolean>,
         writeConcern:<document>})

**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。
 *  **writeConcern **:（可选）抛出异常的级别。

**示例：**

首先插入两条数据：

> db.col.insert(\{

... title:'MongoDB Teach',

... by:'菜鸟教程',

... url:'http://www.runoob.com',

... tags:\['mongodb','database','NoSQL'\],

... likes:100

... \})

WriteResult(\{ "nInserted" : 1 \})

> db.col.insert(\{ title:'MongoDB Teach', by:'菜鸟教程', url:'http://www.runoob.c

om', tags:\['mongodb','database','NoSQL'\], likes:100 \})

WriteResult(\{ "nInserted" : 1 \})

> db.col.find()

\{ "\_id" : ObjectId("577f52430fe1ae602eda9341"), "title" : "MongoDB Teach", "by"

: "菜鸟教程", "url" : "http://www.runoob.com", "tags" : \[ "mongodb", "database",

"NoSQL" \], "likes" : 100 \}

\{ "\_id" : ObjectId("577f52460fe1ae602eda9342"), "title" : "MongoDB Teach", "by"

: "菜鸟教程", "url" : "http://www.runoob.com", "tags" : \[ "mongodb", "database",

"NoSQL" \], "likes" : 100 \}

然后，删除：

> db.col.remove(\{'title':'MongoDB Teach'\})

WriteResult(\{ "nRemoved" : 2 \})

可以看到，两条都删除了，即：满足条件的都删除。因此，如果想清空表：

> db.col.remove(\{\})

相当于  SQL 的 truncate 命令.

from: [http://www.runoob.com/mongodb/mongodb-update.html][http_www.runoob.com_mongodb_mongodb-update.html]

[http_www.runoob.com_mongodb_mongodb-update.html]: http://www.runoob.com/mongodb/mongodb-update.html

mongodb-基础-update-remove

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