下面是一个完整的示例代码,用于将name字段为空的文档的值更新为anotherField字段的值。 // 查询需要更新的文档constdocuments=db.collection.find({name:""})// 更新字段值documents.forEach(document=>{db.collection.updateOne({_id:document._id},// 查询条件[{$set:{name:document.anotherField}}]// 更新...
4 mongodb update field a to be value of field b 4 MongoDB replace value during aggregation 1 Update particular field in mongodb of all documents with reference to its current value 11 MongoDB: Update field using value from another field 2 Mongo db 4.2: replace field of an array...
参考资料:https://stackoverflow.com/questions/3974985/update-mongodb-field-using-value-of-another-field/28460030 mongo 4.2 类似,update table set filed = othe
updateDef = updateDef.Set(x => x.Data, newDataModel); The problem is that I want the "historyObject" to be automatically gotten from the current document's "data" field. Any ideas? Current workaround To work around this problem I'm currently fetching the document firs...
Field Type Description customData document Optional. Any arbitrary information. roles array Optional. The roles granted to the user. An update to therolesarray overrides the previous array's values. pwd string Optional. The user's password. The value can be either: ...
|键值(key-value)存储数据库 |Tokyo Cabinet/Tyrant, Redis, Voldemort, Oracle BDB |内容缓存,主要用于处理大量数据的高访问负载,也用于一些日志系统等等。 |Key 指向 Value 的键值对,通常用hash table来实现 |查找速度快 |数据无结构化,通常只被当作字符串或者二进制数据 | ...
db.updateRole(rolename, update, writeConcern) Updates a user-defined role. The db.updateRole() method must run on the role’s database. An update to a field completely replaces the previous field’s values. To grant or remove roles or privileges without replacing all values, use one or ...
updateOne() and updateMany(): Update one or more documents according to some criteria deleteOne() and deleteMany(): Delete documents from the collection 最常见的MongoDB查询语言命令,以及我们将介绍的命令如下。 find():查找和选择匹配简单或复杂条件的文档的查询 ...
使用$indexOfCP检查子字符串中是否存在matchingWord。如果matchingWord不在子字符串中，则将返回-1.$map此结果从matchingWords数组返回到布尔数组。使用$anyElementTrue检查搜索字符串中的任何单词。
this.isInSubObject: True if we're traversing an object that's somewhere within another object. this.isModifier: True if this is running on a MongoDB update document (also known as "modifier" object). this.isSet: True if the field is already set in the document this.key: The schema key...