Fix “WRONGTYPE Operation against a key holding the wrong kind of value” When Calling SUNION or SUNIONSTORE in Redis

If you’re getting an error that reads “WRONGTYPE Operation against a key holding the wrong kind of value” when calling either the SUNION command or the SUNIONSTORE command in Redis, it’s probably because you’re passing a key with the wrong data type.

To fix this issue, make sure that each key that you pass holds a set.

Read more

How to Get a Key’s Type in Redis

If you know the name of a key in Redis, but you want to find out it’s type (eg, string, list, hash, set, etc), look no further than the TYPE command. This command returns the string representation of the type of the value at the given key.

Read more