> db.source_collection.find().forEach( function(x){db.collection_copy.insert(x)} ); 移动: 1 2 3 > use admin switched to db admin > db.runCommand({renameCollection: 'db1.source_collection', to: 'db2.target_collection'}) // who'd think rename could move? 其他答案更适合于复制集合,...
Studio 3T’s built-in copy and paste collection feature is the fastest way to copy (or duplicate) an entire MongoDB collection to another database. The ability to copy collections is useful for migrating data, backing up data, setting up development or test environments, and creating subsets ...
You can use$mergeto move data from a time series collection to another collection. distinct Command Due to the unique data structure of time series collections, MongoDB can't efficiently index them for distinct values. Avoid using thedistinctcommand ordb.collection.distinct()helper method on time...
orders.insert_one({'order_id':"123",'user':"tony",'order_info':{}},session=s1)""" another session get user orders """withclient.start_session(causal_consistency=True)ass2:s2.advance_cluster_time(s1.cluster_time)# hybird logical clock s2.advance_operation_time(s1.operation_time)orders=...
Studio 3T’s migration tool supports the major SQL databases, including Oracle, Microsoft SQL Server, Sybase, MySQL, PostgreSQL and IBM DB2, making it easier for you to move your data from one platform to another. Fix Your Schema While Migrating ...
MongoDB's blog includes technical tutorials, MongoDB best practices, customer stories, and industry news related to the leading non-relational database.
In order to achieve good quality unit tests that test a single unit and ensure the tests do not leak into third party dependencies, we had previously wrapped all of the mgo structs that we would be using, including mgo.Database, mgo.Collection, mgo.Query and mgo.Session. The wrappers arou...
Migrate MongoDB (standalone instance) to MongoDB (all architectures),Data Transmission Service:This topic explains how to use Data Transmission Service (DTS) for a full migration from a MongoDB database (standalone instance) to a MongoDB database (all ar
但是,这里是 MongoDB 和标准不太一样的地方,MongoDB 的因果一致性提供的是 Client-centric 一致性模型下的承诺,而非 Data-centric。这么做主要还是从系统开销角度考虑,实现 Data-centric 下的因果一致性所需要的全局一致性视图代价过高,在真实的场景中,Client-centric 一致性模型往往足够了,关于这一点的详细论述可...
方法: 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