https://docs.mongodb.com/manual/reference/operator/update/push/#append-multiple-values-to-an-array 我运行了这个代码：将多个字符串添加到数组中而不重复的一种方法是使用$addToSet运算符和$each修饰符：如果要推送新元素而不篡改现有字符串数组，请尝试以下代码段：
Runtestunit.native(function(err, runtestunit){ runtestunit.find({sessionID : sessionData.id_}).toArray(function(err, results) { if (err) return res.serverError(err); runtestunit.update({ _id: results[0]._id }, { $push: { screenshots: filename } }, function(err, screenshots) { ...
Append Multiple Values to an Array Use$pushwith the$eachmodifier to append multiple values to the array field. The following example appends each element of[ 90, 92, 85 ]to thescoresarray for the document where thenamefield equalsjoe: ...
['huangbo','zhangyixing']}}})//WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 0 }){ $push: { <field>: { $each: [ <value1>, <value2> ... ] } } }Use with the $push operator to append multiple values to an array .db.grade1.update({_id:3}, {$push...
Returns an average of all the values in a group. $push Returns an array of all values for the selected field among for each document in that group. $sum Returns the sum of all the values in a group. Bool类型聚合操作符 Name Description $and Returns true only when all values in its ...
Use update operators to modify MongoDB documents. You can set field values, manipulate arrays, and more.
POSIX多线程的使用方式中, 有一种很重要的方式---流水线(亦称为“管道”)方式,“数据元素”流串行地被一组线程按顺序执行。它的使用架构可参考下图: 以面向对象的思想去理解,整个流水线,可以理解为一个数据传输的管道;该管道中的每一个工作线程,可以理解为一个整个流水线的一个工作阶段stage,这些工作线程之间的...
to use for transforming arrays of documents and should be preferred when dealing with multiple objects.updatereturns an array of all paths that were updated. It also supportsarrayFiltersfor applicable operators. To detect whether a change occurred you can check the length of the returned array. ...
Operation ID: InsertMultipleDocuments You can add more than one document at a time by using the insertMany endpoint. In that case, you must use the documents property in the body of the request to specify the array of documents you want to insert into the collection. Parameters 展开表 ...
The first parameter of theinsertMany()method is an array of objects, containing the data you want to insert. It also takes a callback function where you can work with any errors, or the result of the insertion: Example Insert multiple documents in the "customers" collection: ...