MongoDB快速入门笔记(六)之MongoDB的文档修改操作

数据库发布日期：2024/12/28 浏览次数：1

正在浏览：MongoDB快速入门笔记(六)之MongoDB的文档修改操作

MongoDB

MongoDB 是一个开源的文档数据库，并领先的 NoSQL 数据库。 MongoDB 是由 c++语言编写。

文档

文档是一组键 - 值对。文件动态模式。动态模式是指，在相同集合中的文档不需要具有相同的字段或结构组的公共字段的集合的文档，可以容纳不同类型的数据。

db.集合名称.update({query},{update},upsert, multi})
query:过滤条件
update:修改内容
upsert：如果不存在查询条件查出的记录，是否插入一条数据，默认是false
multi：是否只修改查询条件查出的第一条记录，默认是false

> db.student.update({_id:1}, {name:"zhang"})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.student.find()
{ "_id" : 1, "name" : "zhang" }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }

把整条数据都修改了，如果修改内容中没有设置age字段，则以前的age也取消了，数据全部修改

局部修改

$set:如果存在键则修改，如果不存在键则添加

> db.student.update({_id: 1},{$set:{name:"zhangsan", age: 26}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.student.find()
{ "_id" : 1, "name" : "zhangsan", "age" : 26 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }

id重复时无法修改

> db.student.update({_id:1},{_id:0, name:"zhangsanzhangsan"})
WriteResult({
"nMatched" : 0,
"nUpserted" : 0,
"nModified" : 0,
"writeError" : {
"code" : 16837,
"errmsg" : "The _id field cannot be changed from {_id: 1.0} to {_id: 0.0}."
}
})
> db.student.find()
{ "_id" : 1, "name" : "zhangsan", "age" : 26 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }

第三个参数默认为false，如果查不到数据false时不执行任何操作，true时往数据库里新插入一条数据

> db.student.update({_id:7},{_id:7, name: "songjiu", age:32})
WriteResult({ "nMatched" : 0, "nUpserted" : 0, "nModified" : 0 })
> db.student.update({_id:7},{_id:7, name: "songjiu"}, true)
WriteResult({ "nMatched" : 0, "nUpserted" : 1, "nModified" : 0, "_id" : 7 })
> db.student.find()
{ "_id" : 1, "name" : "zhangsan", "age" : 26 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 7, "name" : "songjiu", "age" : 32 }

第四个参数默认为false，false时表示只修改查询到的第一条数据，true时表示修改查询到的所有数据

> db.student.update({age:32}, {$set:{age:33}}, false, false)
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.student.find()
{ "_id" : 1, "name" : "zhangsan", "age" : 26 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 33 }
{ "_id" : 7, "name" : "songjiu", "age" : 32 }
> db.student.update({age:33}, {$set:{age:32}}, false, true)
WriteResult({ "nMatched" : 2, "nUpserted" : 0, "nModified" : 2 })
> db.student.find()
{ "_id" : 1, "name" : "zhangsan", "age" : 26 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 32 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 7, "name" : "songjiu", "age" : 32 }
> db.student.update({age:32}, {$set:{age:33}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.student.find()
{ "_id" : 1, "name" : "zhangsan", "age" : 26 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 7, "name" : "songjiu", "age" : 32 }

$inc:在原来的基础上加多少

> db.student.update({_id:7}, {$inc:{age:-1}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.student.find()
{ "_id" : 1, "name" : "zhangsan", "age" : 26 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 7, "name" : "songjiu", "age" : 31 }

$unset:去掉某个键

> db.student.update({_id:7},{$unset:{age:1}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.student.find()
{ "_id" : 1, "name" : "zhangsan", "age" : 26 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 7, "name" : "songjiu" }

针对数组类型的操作

$push:当数据中不存在键时，创建数组类型的键并插入该值;如果存在该键，并且该键是数组类型时，则在此数组类型的数据上追加;如果存在该键，并且该键不是数组类型时，会报错。
$pushAll:批量往数组中追加
$addToSet:数组中有该值时不追加，没有该值时追加

> db.student.update({_id: 7},{$push:{skill:"java"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.student.find()
{ "_id" : 1, "name" : "zhangsan", "age" : 26 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 7, "name" : "songjiu", "skill" : [ "java" ] }
> db.student.update({_id: 7},{$push:{skill:"mongodb"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.student.find()
{ "_id" : 1, "name" : "zhangsan", "age" : 26 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 7, "name" : "songjiu", "skill" : [ "java", "mongodb" ] }
> db.student.update({_id: 7},{$push:{name:"111"}})
WriteResult({
"nMatched" : 0,
"nUpserted" : 0,
"nModified" : 0,
"writeError" : {
"code" : 16837,
"errmsg" : "The field 'name' must be an array but is of type String in document {_id: 7.0}"
}
})
> db.student.update({_id: 7},{$pushAll:{skill:["js","C++","java"]}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.student.find()
{ "_id" : 1, "name" : "zhangsan", "age" : 26 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 7, "name" : "songjiu", "skill" : [ "java", "mongodb", "js", "C++", "java" ] }
> db.student.update({_id:7},{$addToSet:{skill:"mongodb"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 0 })
> db.student.find()
{ "_id" : 1, "name" : "zhangsan", "age" : 26 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 7, "name" : "songjiu", "skill" : [ "java", "mongodb", "js", "C++", "java" ] }

$pop:删除数组的第一个或最后一个元素，值为-1时是删除第一个元素，值为1时是删除最后一个元素。

$pull:删除数组中的某一个指定的数值

$pullAll:删除数组中多个指定的数值

> db.student.update({_id:7},{$pop:{skill:1}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.student.find()
{ "_id" : 1, "name" : "zhangsan", "age" : 26 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 7, "name" : "songjiu", "skill" : [ "java", "mongodb", "js", "C++" ] }
> db.student.update({_id:7},{$pop:{skill:-1}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.student.find()
{ "_id" : 1, "name" : "zhangsan", "age" : 26 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 7, "name" : "songjiu", "skill" : [ "mongodb", "js", "C++" ] }
> db.student.update({_id:7},{$pull:{skill:"js"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.student.find()
{ "_id" : 1, "name" : "zhangsan", "age" : 26 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 7, "name" : "songjiu", "skill" : [ "mongodb", "C++" ] }
> db.student.update({_id:7},{$pullAll:{skill:["js"]}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 0 })
> db.student.find()
{ "_id" : 1, "name" : "zhangsan", "age" : 26 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 7, "name" : "songjiu", "skill" : [ "mongodb", "C++" ] }
> db.student.update({_id:7},{$pullAll:{skill:["mongodb","C++"]}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.student.find()
{ "_id" : 1, "name" : "zhangsan", "age" : 26 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 7, "name" : "songjiu", "skill" : [ ] }

上一篇：JavaScript按日期查询MongoDB中的数据的要点示例

下一篇：MongoDB中的主从同步配置和mongod相关启动命令讲解

一句话新闻

微软与英特尔等合作伙伴联合定义“AI PC”：键盘需配有Copilot物理按键

几个月来，英特尔、微软、AMD和其它厂商都在共同推动“AI PC”的想法，朝着更多的AI功能迈进。在近日，英特尔在台北举行的开发者活动中，也宣布了关于AI PC加速计划、新的PC开发者计划和独立硬件供应商计划。
在此次发布会上，英特尔还发布了全新的全新的酷睿Ultra Meteor Lake NUC开发套件，以及联合微软等合作伙伴联合定义“AI PC”的定义标准。