In Redis, we have several options for incrementing a key. For example, if we set a key to 1, we can increment it by 1 to make 2. Or we can increment it by whatever amount we desire.
Below are four ways to increment a key in Redis.
Redis SUBSTR Equivalent
Many SQL databases have a SUBSTR() or equivalent function that returns a substring from a specified string.
Redis has a SUBSTR command, but it was deprecated in Redis 2.0.0.
However, Redis also has the GETRANGE command, that basically does the same thing. Basically, anything that was possible with the Redis SUBSTR command, is now possible with the GETRANGE command.
And the GETRANGE command does basically the same thing that most of the SUBSTR() and SUBSTRING() functions do in the SQL world – gets a substring from a string.
4 Ways to Return a Key’s Expiry in Redis
There are several ways to return a key’s expiry in Redis. The method used depends on how we want the expiry to be returned.
We can use the TTL command to return the timeout in seconds. We can alternatively use the PTTL command to return it in milliseconds. Another way to do it is to use the EXPIRETIME which returns the absolute Unix timestamp of the key in seconds, or the PEXPIRETIME command which returns the absolute Unix timestamp of the key in milliseconds.
Redis OBJECT ENCODING Command Explained
In Redis, the OBJECT ENCODING command returns the internal encoding for the Redis object stored at the specified key.
How to Increment a Floating Point Number in Redis
The INCR command is commonly used in Redis to increment a value by one. And the INCRBY command can be used to increment a valued by a specified integer. But neither of those commands let us work with floating point numbers.
If we want to use floating point numbers, we can use the INCRBYFLOAT command.
Redis RANDOMKEY Command Explained
In Redis, the RANDOMKEY command returns a random key from the currently selected database.
Redis KEYS Command Explained
In Redis, the KEYS command returns all keys in the database matching a given pattern.