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…
mongodb操作文件,主要是通过GridFS类.存储文件主要存放在fs中,其中的fs是数据库默认的.并且GridFS是直接与数据库打交道,与collection集合无关. =============== https://docs.mongodb.com/manual/core/gridfs/ When to Use GridFS In MongoDB, use GridFS for storing files larger than 16 MB. =======================…
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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…