I have created a redis lua script to execute a command based on key data type :-
local keyType = redis.call("TYPE", KEYS[1])
if (keyType == "string")
then
return redis.call("GET",KEYS[1])
else
return nil
end
It is returning null every time I am executing it.Can any please help in correcting the script.
The response to redis.call returns as a table that looks like this: {"ok": "string"} (if the type is a string of course)
So in order to properly check, you should change your code to:
local keyType = redis.call("TYPE", KEYS[1]).ok
and the rest of the code will work fine.
The issue is this: the TYPE command is one of the few commands that return a "simple string" or "status" redis reply (see the redis protocol specs for the response types). In the redis lua documentation it's stated that:
Redis status reply -> Lua table with a single ok field containing the status
Which is what happened here.
Using [1] will also work.local keyType = redis.call("TYPE", KEYS[1]) return keyType[1]
