从4.2版开始，copyDatabase已弃用。从现在开始，我们应该使用:mongump和mongorestore。

假设我们有一个名为:old_name的数据库，我们希望将其重命名为new_name。

首先，我们必须转储数据库:

mongodump --archive="old_name_dump.db" --db=old_name

如果您必须作为用户进行身份验证，则使用:

mongodump -u username --authenticationDatabase admin \
          --archive="old_name_dump.db" --db=old_name

现在我们将db转储为一个名为:old_name_dump.db的文件。

用新名称恢复:

mongorestore --archive="old_name_dump.db" --nsFrom="old_name.*" --nsTo="new_name.*"

同样，如果您需要进行身份验证，请将以下参数添加到命令中:

-u username --authenticationDatabase admin 

参考:https://docs.mongodb.com/manual/release-notes/4.2-compatibility/ # remove-support-for-the-copydb-and-clone-commands

在将所有数据放入管理数据库的情况下(您不应该这样做)，您将注意到db.copyDatabase()将不起作用，因为您的用户需要许多特权，而您可能不想给予它。下面是一个手动复制数据库的脚本:

use old_db
db.getCollectionNames().forEach(function(collName) {
    db[collName].find().forEach(function(d){
        db.getSiblingDB('new_db')[collName].insert(d); 
    }) 
});

不，没有。见https://jira.mongodb.org/browse/server - 701

Unfortunately, this is not an simple feature for us to implement due to the way that database metadata is stored in the original (default) storage engine. In MMAPv1 files, the namespace (e.g.: dbName.collection) that describes every single collection and index includes the database name, so to rename a set of database files, every single namespace string would have to be rewritten. This impacts: the .ns file every single numbered file for the collection the namespace for every index internal unique names of each collection and index contents of system.namespaces and system.indexes (or their equivalents in the future) other locations I may be missing This is just to accomplish a rename of a single database in a standalone mongod instance. For replica sets the above would need to be done on every replica node, plus on each node every single oplog entry that refers this database would have to be somehow invalidated or rewritten, and then if it's a sharded cluster, one also needs to add these changes to every shard if the DB is sharded, plus the config servers have all the shard metadata in terms of namespaces with their full names. There would be absolutely no way to do this on a live system. To do it offline, it would require re-writing every single database file to accommodate the new name, and at that point it would be as slow as the current "copydb" command...

你可以这样做，如果你使用MongoDB < 4.2 (ref):

db.copyDatabase("db_to_rename","db_renamed","localhost")
use db_to_rename
db.dropDatabase();

编者按:这与问题本身使用的方法相同，但已被证明对其他人有用。

我试过了。

db.copyDatabase('DB_toBeRenamed','Db_newName','host') 

然后才知道它已经被mongo社区弃用了，尽管它创建了备份或重命名了DB。

WARNING: db.copyDatabase is deprecated. See http://dochub.mongodb.org/core/copydb-clone-deprecation
{
        "note" : "Support for the copydb command has been deprecated. See 
        http://dochub.mongodb.org/core/copydb-clone-deprecation",
        "ok" : 1
}

所以不相信上面的方法，我不得不采取转储本地使用下面的命令

mongodump --host --db DB_TobeRenamed --out E://FileName/

连接到Db。

use DB_TobeRenamed

然后

db.dropDatabase()

然后使用命令恢复数据库。

mongorestore -host hostName -d Db_NewName E://FileName/

mongoshdeprecederror: [COMMON-10003] copyDatabase()已被移除，因为它在MongoDB 4.0中已弃用