MongoDB中的Java API:com.mongodb.DBCollection.Save()和com.mongodb.DBCollection.Insert()之间的区别? [英] MongoDB Java API: Difference between com.mongodb.DBCollection.Save() and com.mongodb.DBCollection.Insert()?
问题描述
看起来这两种方法既节省BasicDbObject到集合instance.What是这两种方法之间的区别?
com.mongodb.DBCollection.Insert()
com.mongodb.DBCollection.Save()
It looks these two methods both save a BasicDbObject to a collection instance.What is the difference between these two methods? com.mongodb.DBCollection.Insert() com.mongodb.DBCollection.Save()
推荐答案
保存只能保存一个对象在同一时间。如果提供_id,它已经存在,新的文件将覆盖previously现有之一。如果它不存在,它会做一个插入。
Save can only save one object at a time. If _id is provided and it already exists, the new document will overwrite the previously existing one. If it doesn't exist, it will do an insert.
插入可以采取单个对象或对象的ArrayList和做他们的批量插入。
Insert can take a single object or an ArrayList of objects and do a "bulk insert" of them.
如果你给一个现有的_id到插入就会造成重复ID例外。
If you give an existing _id to an insert it will cause a duplicate Id exception.
这篇关于MongoDB中的Java API:com.mongodb.DBCollection.Save()和com.mongodb.DBCollection.Insert()之间的区别?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!