Deletions are a little more complex, because we also want to delete the reverse mapping for the key we're deleting.

删除函数略微有些复杂，因为我们还想删除正在删除的键的反向映射。

youdao

You also need to delete all mapping groups that are empty.

你还需要删除说有空的映射组。

youdao

Delete the existing mapping to the field ExternalSystemID.

删除已有的到字段ExternalSystemID的映射。

youdao

London, England (CNN) -- Google agreed Friday to delete data it inadvertently collected from unsecured Wi-Fi networks when compiling its Street View mapping service in Britain, authorities said.

CNN: Google to delete inadvertent Street View data