ERR syntax error while performing SCAN operations in Redis using Spring Data Redis

Question

While working with Redis using Spring Data Redis, I tried to scan hash data in my server (similar to HSCAN in CLI) -

Cursor<Entry<Object,Object>> scan = redisTemplate.opsForHash().scan("student", new ScanOptionsBuilder().count(0).match("*").build());

While running this I get the below error -

redis.clients.jedis.exceptions.JedisDataException: ERR syntax error

Can anyone help me how to solvw this.

There are many related discussions but none of them provide clear answer.

Answer 1

You should use count > 0, or not using count at all (default is 10).

From looking at ScanOptions.java, if count is used, it is passed to the command without any checks.

A quick check on redis-cli shows COUNT 0 throws ERR syntax error.

> hset hash1 f v
(integer) 1
> hscan hash1 0 MATCH * COUNT 0
(error) ERR syntax error
> hscan hash1 0 MATCH * COUNT 1
1) "0"
2) 1) "f"
   2) "v"

See SCAN > The COUNT option for more details. It doesn't state it has to be greater than 0 though but makes sense it should.