How to Copy a Key’s Value to Another Key in Redis

As from Redis 6.2.0, we can use the COPY command whenever we need to copy a key’s value to another key.

Example

Suppose we set the following key:

SADD names Meow Fluffy Scratch

Result:

(integer) 3

In this case, I created a set with three members.

Let’s take a look:

SMEMBERS names

Result:

1) "Meow"
2) "Scratch"
3) "Fluffy"

We can now use the COPY command to copy this key:

COPY names logins

Result:

(integer) 1

Here, I copied the names key to one called logins.

Let’s check the contents of the new key:

SMEMBERS logins

Result:

1) "Meow"
2) "Scratch"
3) "Fluffy"

As expected, it contains the same members that our names key contains.

Note that if the destination key already exists, nothing is copied. However we can overcome this by using the REPLACE option. See Redis COPY Command Explained for an example.