Remove: remove the wand with the name of "Doom Bringer" from our wandscollection. db.wands.remove({name: "Doom Bringer"}) >> WriteResult({'ngRemoved': 1}) When we removed the "Doom Bringer" wand, we noticed that it had…
MongoDB的update问题(JAVA)——怎么一次更新所有的相同记录用如下这个函数:public WriteResult update(DBObject q, DBObject o, boolean upsert, boolean multi) throws MongoException官方API写的是:upsert - if the database should create the element if it does not existmulti - if the upda…
Update操作只作用于集合中存在的文档.MongoDB提供了如下方法来更新集合中的文档: db.collection.update() db.collection.updateOne() New in version 3.2 db.collection.updateMany() New in version 3.2 db.collection.replaceOne() New in version 3. 你可以通过指定criteria或者filter来指定你想更新的文档: update函数执行…