redis cli hset

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Redis CLI HSET

Redis is an open-source, in-memory data structure store that can be used as a database, cache, and message broker. It provides various data structures, including strings, lists, sets, hashes, and more. In this article, we will focus on the hset command in the Redis CLI, which is used to set the value of a field in a hash.

What is a hash in Redis?

A hash is a key-value data structure in Redis. It is similar to a dictionary or a map, where each field is associated with a value. Hashes are useful when you want to store and retrieve related data together, instead of using separate keys for each piece of information.

Using the `hset` command

The hset command is used to set the value of a field in a hash. Its syntax is as follows:

hset key field value

key: The key of the hash.
field: The field within the hash.
value: The value to be set for the field.

Let's say we have a hash named user with the fields name, age, and email. We can use the hset command to set the values for these fields as follows:

> hset user name "John Doe"
(integer) 1
> hset user age 30
(integer) 1
> hset user email "john@example.com"
(integer) 1

In the above example, we first set the value of the name field to "John Doe", then the age field to 30, and finally the email field to "john@example.com". The command returns (integer) 1 to indicate that the value was set successfully.

Retrieving values from a hash

To retrieve the values from a hash, we can use the hget command. For example, to get the value of the name field from the user hash:

> hget user name
"John Doe"

Similarly, we can retrieve the values of other fields:

> hget user age
"30"
> hget user email
"john@example.com"

Updating values in a hash

If we want to update the value of a field in a hash, we can simply use the hset command again with the new value. For example, to update the email address of the user hash:

> hset user email "john.doe@example.com"
(integer) 0

The command returns (integer) 0 to indicate that the field already existed and the value was updated.

Conclusion

In this article, we explored the hset command in the Redis CLI, which is used to set the value of a field in a hash. We learned how to use the command to set, retrieve, and update values in a hash. Hashes are a powerful data structure in Redis that allow us to store related data together and perform efficient operations on them.

Remember to install and start Redis, and then use the Redis CLI to interact with the server and execute the hset command. Redis has a rich set of commands and data structures, so make sure to explore them further to leverage the full potential of Redis in your applications.