Mongodb使用学习笔记(三)_随笔

Mongodb使用学习笔记(三)

文章目录

- Mongodb使用学习笔记(三)
- - 1. MongoDB 更新文档
  - - 1.1 update()
    - 1.2 save()

Mongodb使用学习笔记(三) 1. MongoDB 更新文档

参考：MongoDB 更新文档
官方文档（要梯子）
MongoDB更新文档有update()和save()方法。update主要更新已存在的文档，save主要是存在"_id"的数据就更新，没有就新增。

1.1 update()

参数结构：

db.collection.update({
	,
	,
	{
		upsert: ,
     	multi: ,
     	writeConcern: 
	}
})

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 *** 作符（如 , , ,inc…）等，也可以理解为sql update查询内set后面的

更新的 *** 作符有：

MongoDB 原子 *** 作
1.不包含 *** 作：新的文档会直接将旧文档数据覆盖。
2.$inc：给相应的字段加上参数所给的值。
3.$set：给相应的字段设置参数所给的值。
- 如果该字段没有在文档中，文档会增加该字段的数据
4.$unset：删除指定的字段。
5.$rename：重命名指定的字段。
6.$push：对数组元素的 *** 作符，只能对数组元素的字段使用，否则会报错，向数组中push单个值。push是增加数组元素的 *** 作。
- 在测试的时候，向已存在的非数组的元素进行push *** 作会报错。但是如果文档中未存在该字段，会新增该数组元素。
7.$each：对数组元素的 *** 作符，只能对数组元素的字段使用，否则会报错，向数组中push多个值。
- $each要和$pash一起用
8.$pop：对数组元素的 *** 作符，只能对数组元素的字段使用，否则会报错，向数组中pop单个值。pop是删除数组元素的 *** 作。只能删除第一个或者最后一个元素。-1表示删除第一个，1表示删除最后一个。
- 不能对某个指定值进行删除
9.$pullAll：对数组元素的 *** 作符，只能对数组元素的字段使用，否则会报错，数组删除多个指定的值。

10.$pull：删除数组中符合条件的值。和pullAll不一样的是，pullAll指定删除数组中存在的哪一个（些）值，在中括号里面一个个列出来，pull删除的是符合条件的值，写的是条件的表达式。

条件可以用正则表达式，也可以用$in之类的
上述 *** 作记录：

> use test
switched to db test
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware6asdg", "serial_number" : "abcdef", "type" : "switch", "city" : "hn" }
> db.hardware.update({name:/hardware/},{"name":"hardware1","serial_number":"000001","type":"switch","port":["01","02","03"],"count":1})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware1", "serial_number" : "000001", "type" : "switch", "port" : [ "01", "02", "03" ], "count" : 1 }
> db.hardware.update({name:/hardware/},{$inc:{"count":1}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware1", "serial_number" : "000001", "type" : "switch", "port" : [ "01", "02", "03" ], "count" : 2 }
> db.hardware.update({name:/hardware/},{$set:{"name":"hardware11"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "01", "02", "03" ], "count" : 2 }
> db.hardware.update({name:/hardware/},{$set:{"fieldtest":"fieldtest"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "01", "02", "03" ], "count" : 2, "fieldtest" : "fieldtest" }
> db.hardware.update({name:/hardware/},{$unset:{"fieldtest":"fieldtest"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "01", "02", "03" ], "count" : 2 }
> db.hardware.update({name:/hardware/},{$rename:{"count":"countnumber"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "01", "02", "03" ], "countnumber" : 2 }
> db.hardware.update({name:/hardware/},{$push:{"port":"04"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "01", "02", "03", "04" ], "countnumber" : 2 }
> db.hardware.update({name:/hardware/},{$push:{"count":"04"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "01", "02", "03", "04" ], "countnumber" : 2, "count" : [ "04" ] }
> db.hardware.update({name:/hardware/},{$push:{"countnumber":"04"}})
WriteResult({
        "nMatched" : 0,
        "nUpserted" : 0,
        "nModified" : 0,
        "writeError" : {
                "code" : 2,
                "errmsg" : "The field 'countnumber' must be an array but is of type double in document {_id: ObjectId('61a8674e83e24c27ab4ce164')}"
        }
})
> db.hardware.update({name:/hardware/},{$each:{"port":["05","06"]}})
WriteResult({
        "nMatched" : 0,
        "nUpserted" : 0,
        "nModified" : 0,
        "writeError" : {
                "code" : 9,
                "errmsg" : "Unknown modifier: $each. Expected a valid update modifier or pipeline-style update specified as an array"
        }
})
> db.hardware.update({name:/hardware/},{$push:{"port":{$each:["05","06"]}})
...
...
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "01", "02", "03", "04" ], "countnumber" : 2, "count" : [ "04" ] }
>  db.hardware.update({name:/hardware/},{$push:{"port":{$each:["05","06"]}})
... ^C

> db.hardware.update({name:/hardware/},{$push:{"port":$each:["05","06"]})
... ^C

> db.hardware.update({name:/hardware/},{$push:{"port":{$each:["05","06"]}}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "01", "02", "03", "04", "05", "06" ], "countnumber" : 2, "count" : [ "04" ] }
> db.hardware.update({name:/hardware/},{$pop:{"port":"06"}})
WriteResult({
        "nMatched" : 0,
        "nUpserted" : 0,
        "nModified" : 0,
        "writeError" : {
                "code" : 9,
                "errmsg" : "Expected a number in: port: "06""
        }
})
> db.hardware.update({name:/hardware/},{$pop:{"port":1}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "01", "02", "03", "04", "05" ], "countnumber" : 2, "count" : [ "04" ] }
> db.hardware.update({name:/hardware/},{$pop:{"port":-1}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "02", "03", "04", "05" ], "countnumber" : 2, "count" : [ "04" ] }
> db.hardware.update({name:/hardware/},{$pullAll:{"port":["05","06"]}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "02", "03", "04" ], "countnumber" : 2, "count" : [ "04" ] }
> db.hardware.update({name:/hardware/},{$pull:{"port":/6/}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 0 })
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "02", "03", "04" ], "countnumber" : 2, "count" : [ "04" ] }
> db.hardware.update({name:/hardware/},{$pull:{"port":/4/}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "02", "03" ], "countnumber" : 2, "count" : [ "04" ] }

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。

> use test
switched to db test
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "02", "03" ], "countnumber" : 2, "count" : [ "04" ] }
> db.hardware.find({"name":"我是一个宕机的硬件"})
> db.hardware.update({"name":"我是一个宕机的硬件"},{"name":"其实我是一个大帅逼，就是有点丑","city":"gz"},false,false)
WriteResult({ "nMatched" : 0, "nUpserted" : 0, "nModified" : 0 })
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "02", "03" ], "countnumber" : 2, "count" : [ "04" ] }
> db.hardware.update({"name":"我是一个宕机的硬件"},{"name":"其实我是一个大帅逼，就是有点丑","city":"gz"},true,false)
WriteResult({
        "nMatched" : 0,
        "nUpserted" : 1,
        "nModified" : 0,
        "_id" : ObjectId("61b062712eb247ef2a297b6f")
})
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "02", "03" ], "countnumber" : 2, "count" : [ "04" ] }
{ "_id" : ObjectId("61b062712eb247ef2a297b6f"), "name" : "其实我是一个大帅逼，就是有点丑", "city" : "gz" }
>

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。

> db.hardware.update({"city":"gz"},{$set:{"eat":"肠粉"}},false,false)
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "02", "03" ], "countnumber" : 2, "count" : [ "04" ] }
{ "_id" : ObjectId("61b062712eb247ef2a297b6f"), "name" : "其实我是一个大帅逼，就是有点丑", "city" : "gz", "eat" : "肠粉" }
{ "_id" : ObjectId("61b064f1eff9974c5a135de1"), "name" : "路人甲", "city" : "gz" }
{ "_id" : ObjectId("61b064fceff9974c5a135de2"), "name" : "路人乙", "city" : "gz" }
{ "_id" : ObjectId("61b06504eff9974c5a135de3"), "name" : "路人丙", "city" : "gz" }
{ "_id" : ObjectId("61b0650deff9974c5a135de4"), "name" : "路人丁", "city" : "gz" }
> db.hardware.update({"city":"gz"},{$set:{"eat":"肠粉"}},false,true)
WriteResult({ "nMatched" : 5, "nUpserted" : 0, "nModified" : 4 })
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "02", "03" ], "countnumber" : 2, "count" : [ "04" ] }
{ "_id" : ObjectId("61b062712eb247ef2a297b6f"), "name" : "其实我是一个大帅逼，就是有点丑", "city" : "gz", "eat" : "肠粉" }
{ "_id" : ObjectId("61b064f1eff9974c5a135de1"), "name" : "路人甲", "city" : "gz", "eat" : "肠粉" }
{ "_id" : ObjectId("61b064fceff9974c5a135de2"), "name" : "路人乙", "city" : "gz", "eat" : "肠粉" }
{ "_id" : ObjectId("61b06504eff9974c5a135de3"), "name" : "路人丙", "city" : "gz", "eat" : "肠粉" }
{ "_id" : ObjectId("61b0650deff9974c5a135de4"), "name" : "路人丁", "city" : "gz", "eat" : "肠粉" }
>

writeConcern :可选，抛出异常的级别。
- 菜鸟教程下面的评论有网友评论如下，可以看一看。

1.2 save()

根据"_id"来更新或者新增文档数据
“_id"是文档主键。如果存在该”_id"，新文档数据替换旧文档数据。如果没有该id，新增这个新文档数据。
参数格式:
- document : 文档数据。
- writeConcern :可选，抛出异常的级别。
```
db.collection.save(
   ,
   {
     writeConcern: 
   }
)
```
注意，"_id"要一模一样，包括ObjectId的函数
*** 作记录：

> use test
switched to db test
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "02", "03" ], "countnumber" : 2, "count" : [ "04" ] }
{ "_id" : ObjectId("61b062712eb247ef2a297b6f"), "name" : "其实我是一个大帅逼，就是有点丑", "city" : "gz", "eat" : "肠粉" }
{ "_id" : ObjectId("61b064f1eff9974c5a135de1"), "name" : "路人甲", "city" : "gz", "eat" : "肠粉" }
{ "_id" : ObjectId("61b064fceff9974c5a135de2"), "name" : "路人乙", "city" : "gz", "eat" : "肠粉" }
{ "_id" : ObjectId("61b06504eff9974c5a135de3"), "name" : "路人丙", "city" : "gz", "eat" : "肠粉" }
{ "_id" : ObjectId("61b0650deff9974c5a135de4"), "name" : "路人丁", "city" : "gz", "eat" : "肠粉" }
> db.hardware.save({"_id":"61a8674e83e24c27ab4ce164","word":"心情不好，想不通就好好想想吧"})
WriteResult({
        "nMatched" : 0,
        "nUpserted" : 1,
        "nModified" : 0,
        "_id" : "61a8674e83e24c27ab4ce164"
})
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "name" : "hardware11", "serial_number" : "000001", "type" : "switch", "port" : [ "02", "03" ], "countnumber" : 2, "count" : [ "04" ] }
{ "_id" : ObjectId("61b062712eb247ef2a297b6f"), "name" : "其实我是一个大帅逼，就是有点丑", "city" : "gz", "eat" : "肠粉" }
{ "_id" : ObjectId("61b064f1eff9974c5a135de1"), "name" : "路人甲", "city" : "gz", "eat" : "肠粉" }
{ "_id" : ObjectId("61b064fceff9974c5a135de2"), "name" : "路人乙", "city" : "gz", "eat" : "肠粉" }
{ "_id" : ObjectId("61b06504eff9974c5a135de3"), "name" : "路人丙", "city" : "gz", "eat" : "肠粉" }
{ "_id" : ObjectId("61b0650deff9974c5a135de4"), "name" : "路人丁", "city" : "gz", "eat" : "肠粉" }
{ "_id" : "61a8674e83e24c27ab4ce164", "word" : "心情不好，想不通就好好想想吧" }
> db.hardware.save({"_id":ObjectId("61a8674e83e24c27ab4ce164"),"word":"我"})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.hardware.find()
{ "_id" : ObjectId("61a8674e83e24c27ab4ce164"), "word" : "我" }
{ "_id" : ObjectId("61b062712eb247ef2a297b6f"), "name" : "其实我是一个大帅逼，就是有点丑", "city" : "gz", "eat" : "肠粉" }
{ "_id" : ObjectId("61b064f1eff9974c5a135de1"), "name" : "路人甲", "city" : "gz", "eat" : "肠粉" }
{ "_id" : ObjectId("61b064fceff9974c5a135de2"), "name" : "路人乙", "city" : "gz", "eat" : "肠粉" }
{ "_id" : ObjectId("61b06504eff9974c5a135de3"), "name" : "路人丙", "city" : "gz", "eat" : "肠粉" }
{ "_id" : ObjectId("61b0650deff9974c5a135de4"), "name" : "路人丁", "city" : "gz", "eat" : "肠粉" }
{ "_id" : "61a8674e83e24c27ab4ce164", "word" : "心情不好，想不通就好好想想吧" }
>

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Mongodb使用学习笔记(三)

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