How to Use ZINCRBY in Redis: Increment Sorted Set Scores

Use the ZINCRBY command in Redis to increase the score of a member in a sorted set by a specified amount. The syntax is ZINCRBY key increment member, which updates the member's score and returns the new score.

Syntax

The ZINCRBY command increments the score of a member in a sorted set stored at a given key.

• key: The name of the sorted set.
• increment: The amount to add to the member's score (can be positive or negative).
• member: The member whose score you want to increase.

redis

ZINCRBY key increment member

Example

This example shows how to add a member to a sorted set and then increment its score using ZINCRBY.

redis

127.0.0.1:6379> ZADD leaderboard 10 "Alice"
(integer) 1
127.0.0.1:6379> ZINCRBY leaderboard 5 "Alice"
"15"
127.0.0.1:6379> ZRANGE leaderboard 0 -1 WITHSCORES
1) "Alice"
2) "15"

Output

1) "Alice"
2) "15"

Common Pitfalls

Common mistakes when using ZINCRBY include:

• Using a key that does not hold a sorted set, which causes an error.
• Passing a non-numeric increment value, which is invalid.
• Expecting ZINCRBY to add a new member without specifying the increment correctly.

Always ensure the key is a sorted set and the increment is a valid number.

redis

127.0.0.1:6379> SET mykey "value"
OK
127.0.0.1:6379> ZINCRBY mykey 1 "member"
(error) WRONGTYPE Operation against a key holding the wrong kind of value

-- Correct usage --
127.0.0.1:6379> ZADD myset 1 "member"
(integer) 1
127.0.0.1:6379> ZINCRBY myset 2 "member"
"3"

Output

(error) WRONGTYPE Operation against a key holding the wrong kind of value
"3"

Quick Reference

Command	Description	Example
ZINCRBY key increment member	Increment member's score in sorted set	ZINCRBY leaderboard 5 "Alice"
ZADD key score member	Add member with score to sorted set	ZADD leaderboard 10 "Alice"
ZRANGE key start stop WITHSCORES	Get members with scores	ZRANGE leaderboard 0 -1 WITHSCORES

Key Takeaways

ZINCRBY increments the score of a member in a sorted set by a given number.

The command returns the new score of the member after incrementing.

Ensure the key is a sorted set to avoid errors.

The increment must be a valid numeric value, positive or negative.

Use ZADD to add members before incrementing if they don't exist.