这段代码会根据条件{ _id: 123 }更新字段field1的值为'new value'。 3. 根据条件更新不同字段 如果你需要根据条件更新不同字段,可以使用类似以下代码: myModel.findOneAndUpdate({_id:123},{$set:{field1:'new value',field2:'another value'}},{new:true},(
update(具体来说,过滤器将作为镜像读发送) 启用/禁用对镜像读取的支持 默认情况下启用镜像读并使用默认的sampling rate(值为0.01)。要禁用镜像读,请将mirrorReads参数设置为{ samplingRate: 0.0 }: db.adminCommand( { setParameter:1, mirrorReads: {samplingRate:0.0} ...
update : update的对象和一些更新的操作符(如, inc...)等,也可以理解为sql update查询内set后面的 upsert : 可选,这个参数的意思是,如果不存在update的记录,是否插入objNew,true为插入,默认是false,不插入。 multi : 可选,mongodb 默认是false,只更新找到的第一条记录,如果这个参数为true,就把按条件查出来多...
使用"local"或"available"读关注的客户端可读取数据,而这些数据后续可能会在副本集故障转移期间进行回滚。 对于多文档事务中的操作,当事务提交时,该事务中进行的所有数据更改都将保存并在事务外部可见。换言之,一个事务不会在回滚其他事务的同时提交某些更改。
Use one of the update operators in the update field to update your documents.Delete DocumentOperation ID: DeleteDocument To delete a single document, use the deleteOne endpoint. Use the filter property in the request body to specify the search criteria. If more than one document matches the ...
MongoDB中的集合查询(获取一组文档中某个字段的不同值列表) 运用方法:DBCollection对象方法中的 distinct() 语句: 语句结构:distinct(key,[query]) key字符串,指定获取哪个字段的不同值;query:包含标准查询选项的对象,指定了要从哪个文档中获取不同的字段值 ...
anotherResult["age"] = 39; things.Update(resultDoc); Console.WriteLine( db["test"]["things"].FindOne( new Document().Append("lastname", "Neward"))); However, it’s always possible to create a new Document instance and manually fill out the _id field to match the ObjectId, if that...
To update a model, you may retrieve it, change an attribute, and use the save method.$user = User::first(); $user->email = 'john@foo.com'; $user->save();There is also support for upsert operations, check https://github.com/jenssegers/laravel-mongodb#mongodb-specific-operations...
If you don't specify an _id field, MongoDB will create a document with an _id that contains a ObjectId value (as per an insert()).If you specify an _id field, it performs an update with { upsert: true }, meaning, it creates a new document if no document matches the query. ...
Any other return value will be used as the field's value. You may also return special pseudo-modifier objects for update operations. Examples are {$inc: 1} and {$push: new Date}. autoValue gotchas If your autoValue for one field relies on the autoValue or defaultValue of another field, ...