Renames key to newkey if newkey does not yet exist. It returns an error when key does not exist.

Note: Before Redis 3.2.0, an error is returned if source and destination names are the same.

@return

@integer-reply, specifically:

• 1 if key was renamed to newkey.
• 0 if newkey already exists.

@examples

SET mykey "Hello"
SET myotherkey "World"
RENAMENX mykey myotherkey
GET myotherkey