MongoDB quickstart notes of vi MongoDB document modification operations

MongoDB

MongoDB is an open source document database and the leading NoSQL database. MongoDB is written in the c++ language.

The document

The document is a set of key-value pairs. File dynamic mode. Dynamic mode refers to documents in the same collection that do not require a collection of common fields with the same fields or structural groups and can hold different types of data.

db. Collection name.update({query},{update},upsert, multi})
query: filtering conditions
update: modify content
upsert: if there is no record found by the query condition, whether to insert 1 data or not, the default is false
multi: whether to modify only the first record found in the query condition, the default is 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 } 

The whole data has been modified. If the age field is not set in the modified content, the previous age is cancelled and the data is all modified

Local modification

$set: modify if there is a key, add if there is no key

> 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 cannot be modified when repeated

> 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 } 

The third parameter is false by default. If the data cannot be found, false will not perform any operation. true will insert a new data into the database

> 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 } 

The fourth parameter is false by default. When false, it means that only the first data queried is modified; when true, it means that all data queried is modified

> 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: how much more

> 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: remove a key

> 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" } 

Operations on array types

$push: when there is no key in the data, create a key of type array and insert the value; If the key exists and the key is an array type, append the data of this array type; If the key exists and is not an array type, an error is reported.
$pushAll: bulk append to array
$addToSet: the value is not appended when it is in the array and appended when it is not

> 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: deletes the first or last element of an array with a value of -1 and the last element with a value of 1.

$pull: deletes a specified value from an array

$pullAll: deletes multiple specified values in the array

> 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" : [ ] }