I thought I’d compile a list of Redis commands that can be used to set strings. Each command has its own specific use, and so the command used will depend on the situation.
In any case, here are 14 commands that set strings in Redis.
Continue readingI decided to compile a list of commands that can be used to get the string value from a key in Redis. These are all string commands – commands that can be used when working with strings. In other words, the assumption is that the key holds a string value.
Continue readingIf we have a key that holds a string value, we can use the GETRANGE command to get a substring from that value.
Redis also has a SUBSTR command that does the same thing, but that was deprecated in Redis 2.0.0, in favour of the GETRANGE command.
In Redis, typically when we want to return a key’s value, we use the GET command. But there’s also a GETEX command (introduced in Redis 6.2.0) that allows us to get the value and return it’s expiry at the same time.
When working with Redis, we have a number of options for setting keys that store string values.
Here are six ways to set a string value in Redis.
Continue readingWhen using the SET command to set a key in Redis, we can use the GET option to return its old value. This allows us to update the value of a key while returning the value that we’re replacing it with.
Note that this option was introduced in Redis 7.0.0, so if it doesn’t work, check your Redis version. If using an earlier version, try the GETSET command instead (which is deprecated from Redis version 6.2.0).
In Redis, we can use the STRLEN command to get the length of a given string value, based on its key.
We can also use the HSTRLEN command to get the string length of a value stored in a hash.
If we need to append a value to a string in Redis, we can use the APPEND command to do just that. All we need to do is call the command with the key name and the value to append.
In Redis, the GET command is typically used to return the value of a single key that holds a string. But what if we need the values from multiple keys?
We can use the MGET command.
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.