MyMessageBox.ShowEasyMessage("Count", "Count Result : " + SystemManager.GetCurrentCollection().Count().ToString()); } else { MongoDB.Driver.IMongoQuery mQuery = MongoDBHelper.GetQuery(Query.QueryConditionList); MyMessageBox.ShowMessage("Count", "Count[With DataView Filter]:" + SystemManager....
// 连接时不指定要连接数据库,需要时从连接中获取需要的数据库 D:\Java\MongoDB\Server\bin>mongo --nodb MongoDB shell version v3.4.6 > db 2017-07-27T20:27:25.181+0800 E QUERY [thread1] ReferenceError: db is not defined : @(shell):1:1 > conn = new Mongo("localhost:27017") connectio...
Query query =newQuery(); if(conditions !=null&& conditions.size() >0) { for(Condition condition : conditions) { query.addCriteria(Criteria.where(condition.getKey()).regex(".*?\\"+condition.getValue().toString()+".*")); } } returncount(query, ProcessLandLog.class); } 最下面,我在...
3).默认游标超过10分钟没用也会别清除 14.13 聚合查询(Count 、Distinct、Group) 1、count 查询结果条数 代码语言:txt 复制 db.persons.find({country:"USA"}).count() 2、Distinct 去重 请查询出persons中一共有多少个国家分别是什么 代码语言:txt 复制 db.runCommand({distinct:"persons",key:"country"})....
{ $group: { _id:null, count: { $sum:1} } } ] ) To get a count of documents that match a query condition, include thematchstageaswell:为了统计满足查询条件的文档数量,可以使用match方法。 db.collection.aggregate( [ { $match:<querycondition>}, ...
Consider a collection with the following index: {a:1,b:1} When performing a count, MongoDB can return the count using only the index if: the query can use an index, the query only contains conditions on the keys of the index,and ...
db.collection.find( { field: value }, { array: {$slice: count } } ); 2.更新操作符 2.1字段更新 $inc 给一个字段增加指定值 { $inc: { <field1>: <amount1>, <field2>: <amount2>, ... } } $mul { $mul: { field: <number> } } ...
vardeptData={"deptno":50,"dname":"乞讨部","loc":"家里蹲","count":60,"avg":9000.0};db.dept.update({"_id":ObjectId("5d0492d3db2a129b32288894")},deptData);WriteResult({"nMatched":1,"nUpserted":0,"nModified":1})db.dept.find();"_id":ObjectId("5d0492d3db2a129b32288894"),...
To use the readConcern level of "majority", you must specify a nonempty query condition. Regardless of the read concern level, the most recent data on a node may not reflect the most recent version of the data in the system. copy copied db.runCommand( { count: "restaurants", query: ...
criteria={"pilots.qualification_time":{"$lt":10}}quick_races=races.count_documents(criteria)quick_races3061 The above query introduces four new features of the MongoDB query language (MQL): You can access sub-fields with dot notation.pilots.qualification_timeextracts the nested qualification time...