替代解决方案:您可以转储您的数据库，并恢复到不同的名称。根据我的经验，它比db.copyDatabase()快得多。

$ mongodump -d old_db_name -o mongodump/
$ mongorestore -d new_db_name mongodump/old_db_name

http://docs.mongodb.org/manual/tutorial/backup-with-mongodump/

这是目前官方推荐的数据库重命名方法，因为copyDatabase在MongoDB 4.2中被删除了:

"copydb"命令已弃用，请使用以下两个命令: mongodb(用于备份数据) Mongorestore(将数据从mongodb恢复到一个新的命名空间)

替代解决方案:您可以转储您的数据库，并恢复到不同的名称。根据我的经验，它比db.copyDatabase()快得多。

$ mongodump -d old_db_name -o mongodump/
$ mongorestore -d new_db_name mongodump/old_db_name

http://docs.mongodb.org/manual/tutorial/backup-with-mongodump/

这是目前官方推荐的数据库重命名方法，因为copyDatabase在MongoDB 4.2中被删除了:

"copydb"命令已弃用，请使用以下两个命令: mongodb(用于备份数据) Mongorestore(将数据从mongodb恢复到一个新的命名空间)

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...

上面的过程很慢，你可以使用下面的方法，但你需要一个集合一个集合地移动到另一个db。

use admin
db.runCommand({renameCollection: "[db_old_name].[collection_name]", to: "[db_new_name].[collection_name]"})

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。

尽管Mongodb没有提供rename Database命令，但它提供了rename Collection命令，该命令不仅修改了集合名称，还修改了数据库名称。

{ renameCollection: "<source_namespace>", to: "<target_namespace>", dropTarget: <true|false>  writeConcern: <document> }

db.adminCommand({renameCollection: "db1.test1", to: "db2.test2"})

此命令只修改元数据，成本非常小，只需要遍历db1下的所有集合，重命名为db2即可实现重命名数据库名称。 你可以在这个Js脚本中完成

var source = "source";
var dest = "dest";
var colls = db.getSiblingDB(source).getCollectionNames();
for (var i = 0; i < colls.length; i++) {
var from = source + "." + colls[i];
var to = dest + "." + colls[i];
db.adminCommand({renameCollection: from, to: to});
}

请谨慎使用该命令

renameCollection具有不同的性能影响，具体取决于目标名称空间。 如果目标数据库与源数据库相同，则 renameCollection只是更改名称空间。这是一个快速的 操作。 如果目标数据库与源数据库不同， renameCollection将源集合中的所有文档复制到 目标集合。根据集合的大小，这个 可能需要更长的时间才能完成。