说明

db.collection.update(query, update, options)

修改一个或多个集合中已经存在的文档记录。这个方法可以修改一个或多个已经存在的文档记录中的指定字段，或替换整个已经存在的文档记录，具体操作由传入的参数（ update parameter）决定。

默认情况下， update() 方法只修改 一个 文档记录。设置 “Multi”选项 参数后可以批量更新匹配查询条件的所有文档记录。

The update() method has the following form:

在 2.6 版更改.

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

The update() method takes the following parameters:

Parameter	Type	Description
query	document	The selection criteria for the update. Use the same query selectors as used in the find() method.
update	document	The modifications to apply. For details see Update方法的参数.
upsert	boolean	Optional. If set to true, creates a new document when no document matches the query criteria. The default value is false, which does not insert a new document when no match is found.
multi	boolean	Optional. If set to true, updates multiple documents that meet the query criteria. If set to false, updates one document. The default value is false. For additional information, see “Multi”选项.
writeConcern	document	Optional. A document expressing the write concern. Omit to use the default write concern. See 安全的写操作. 2.6 新版功能.

在 2.6 版更改: The update() method returns an object that contains the status of the operation.

返回:	更新结果对象 （ 操作结果 ）中包含本次操作的状态。

行为

db.people.update({ name: "Andy" },{name: "Andy",rating: 1,score: 1},{ upsert: true }
)

示例

{ "_id" : 11, "item" : "Divine Comedy", "stock" : 2 }

db.books.update({ item: "Divine Comedy" },{$set: { price: 18 },$inc: { stock: 5 }}
)

{ "_id" : 11, "item" : "Divine Comedy", "price" : 18, "stock" : 7 }

{ _id: 50, item: "TDB", stock: 0, isbn: { group: 11, publisher: 1111, title: 11, digit: 1 } }

db.books.update({ _id: 50 },{ $set: { "isbn.publisher": 2222, "isbn.digit": 0 } }
)

db.books.update( { _id: 11 }, { $unset: { stock: 1 } } )

{"_id" : 22,"item" : "The Banquet","author" : "Dante","price" : 20,"stock" : 4
}

db.books.update({ item: "The Banquet" },{ item: "The Banquet", price: 19 , stock: 3 }
)

{"_id" : 22,"item" : "The Banquet","price" : 19,"stock" : 3
}

db.books.update({ item: "The New Life" },{ item: "The New Life", author: "Dante", price: 15 },{ upsert: true }
)

{"_id" : ObjectId("51e5990c95098ed69d4a89f2"),"author" : "Dante","item" : "The New Life","price" : 15
}

db.books.update({ stock: { $lt: 5 } },{ $set: { reorder: true } },{ multi: true }
)

db.books.update({ stock: { $lt: 5 } },{ $set: { reorder: true } },{multi: true,writeConcern: { w: "majority", wtimeout: 5000 }}
)

{ _id: 11, author: "Dante", item: "Divine Comedy", price: 18, translatedBy: "abc123" }
{ _id: 12, author: "Dante", item: "Divine Comedy", price: 21, translatedBy: "jkl123" }
{ _id: 13, author: "Dante", item: "Divine Comedy", price: 15, translatedBy: "xyz123" }

db.books.update({ item: "Divine Comedy", author: "Dante" },{ $set: { reorder: false, price: 10 } },{ upsert: true, multi: true }
)

{ _id: 11, author: "Dante", item: "Divine Comedy", price: 10, translatedBy: "abc123", reorder: false }
{ _id: 12, author: "Dante", item: "Divine Comedy", price: 10, translatedBy: "jkl123", reorder: false }
{ _id: 13, author: "Dante", item: "Divine Comedy", price: 10, translatedBy: "xyz123", reorder: false }

{ _id: ObjectId("536aa66422363a21bc16bfd7"), author: "Dante", item: "Divine Comedy", reorder: false, price: 10 }

db.bios.update({ _id: 1 },{ $set: { "contribs.1": "ALGOL 58" } }
)

db.bios.update({ _id: 3, "contribs": "compiler" },{ $set: { "contribs.$": "A compiler" } }
)

db.bios.update({ _id: 4, "awards.by": "ACM"  } ,{ $set: { "awards.$.by": "Association for Computing Machinery" } }
)

db.bios.update({ _id: 1 },{$push: { awards: { award: "IBM Fellow", year: 1963, by: "IBM" } }}
)

db.bios.update({ _id: 1 },{$set: { "name.middle": "Warner" },$push: { awards: {award: "IBM Fellow",year: "1963",by: "IBM"}}}
)

操作结果

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

WriteResult({"nMatched" : 1,"nUpserted" : 0,"nModified" : 1,"writeConcernError" : {"code" : 64,"errmsg" : "waiting for replication timed out at shard-a"}
})

WriteResult({"nMatched" : 0,"nUpserted" : 0,"nModified" : 0,"writeError" : {"code" : 7,"errmsg" : "could not contact primary for replica set shard-a"}
})