old_item = db.swuyg.findAndModify({query: {"_id": "aabbccdd"}, fields:{"D": 1,'E':1, 'F':1}, remove: true}) fields里面为1的是要返回的数据。 8、分布式集群部署情况 (1) 细致到collection的显示:sh.status() (2)仅显示分片: use config; db.shards.find() { "_id" : "shard000...
authentication --authenticationDatabase= database that holds the user's credentials --authenticationMechanism= authentication mechanism to use namespace options: -d, --db= database to use -c, --collection= collection to use input options: -f, --fields= comma separated list of field names, e...
db.collection.find({ "key": /^val.*val$/i }) 正则,类似like;“i”忽略大小写,“m”支持多行 db.collection.find({ $or : [{a : 1}, {b : 2} ] }) $or或 (注意:MongoDB 1.5.3后版本可用),符合条件a=1的或者符合条件b=2的数据都会查询出来 db.collection.find({ "key": value , $...
-d,–db:代表连接的数据库; -c,–collection:代表连接数据库中的集合 -f, --fields:代表导入集合中的字段 –type : 代表导入的文件类型,包括csv和json,tsv文件,默认json格式 –file:导入的文件名称 –headerline:导入csv文件时,指明第一行是列名,不需要导入 数据成功导入。 返回人口超过1000万的州 db.zips....
Optional. A query predicate to filter the list of collections. You can specify a query predicate on any of the fields returned by listCollections. nameOnly boolean Optional. A flag to indicate whether the command should return just the name and type (view, collection, or timeseries) or return...
Move an existing collection to a new schema in a few clicks, or tune up your current schema to improve performance. Easily add, delete, rename, reorder, flatten, and extract fields and arrays, without migration scripts. Learn more Task Scheduler ...
The full Mongo shell script of our filtered change stream is available below: conn = new Mongo("mongodb://localhost:27017/demo?replicaSet=rs"); db = conn.getDB("demo"); collection = db.stock; let updateOps = { $match: { $and: [ { "updateDescription.updatedFields.quantity": { $...
$match的语法和查询表达式(db.collection.find())的语法相同 db.articles.aggregate( [ { $match : { score : { $gt : 70, $lte : 90 } } }, { $group: { _id:null, count: { $sum: 1 } } } ] ); $match用于获取分数大于70小于或等于90记录,然后将符合条件的记录送到下一阶段$group管道...
Let’s assume you have a collection with a lot of data in a single document. You have theteamscollection, and you will select just a few fields you want. Query: db.teams.find({}); Output: Use the Projection Method to Select Single or Multiple Fields for All Documents in a MongoDB ...
The findOne action returns the first document in the collection that matches this filter. projection projection object A MongoDB Query Projection. Depending on the projection the returned document will either omit specific fields or include only specified fields or values Returns Разверну...