In this section, we will cover the fundamental commands in Redis that are essential for interacting with the database. These commands will help you perform basic operations such as setting and getting values, deleting keys, and checking the existence of keys.

1. Keys: Unique identifiers for storing data in Redis.
2. Values: The data associated with keys, which can be of various data types (strings, lists, sets, etc.).
3. Commands: Instructions given to Redis to perform operations on keys and values.

The SET command is used to store a value associated with a key, and the GET command retrieves the value of a key.

Example:

Explanation:

• SET mykey "Hello, Redis!": Stores the string "Hello, Redis!" with the key mykey.
• GET mykey: Retrieves the value associated with mykey, which is "Hello, Redis!".

The DEL command is used to delete one or more keys.

Example:

Explanation:

• DEL mykey: Deletes the key mykey and its associated value.

The EXISTS command checks if a key exists in the database.

Example:

Explanation:

• EXISTS mykey: Returns 1 if the key mykey exists, otherwise returns 0.

The INCR and DECR commands increment and decrement the integer value of a key by one, respectively.

Example:

Explanation:

• SET counter 10: Sets the value of counter to 10.
• INCR counter: Increments the value of counter by 1, resulting in 11.
• DECR counter: Decrements the value of counter by 1, resulting in 10.

The MSET command sets multiple keys to multiple values, and the MGET command retrieves the values of multiple keys.

Example:

Explanation:

• MSET key1 "value1" key2 "value2": Sets key1 to "value1" and key2 to "value2".
• MGET key1 key2: Retrieves the values of key1 and key2, which are "value1" and "value2", respectively.

The EXPIRE command sets a timeout on a key. After the timeout, the key will be automatically deleted.

Example:

Explanation:

• SET mykey "Hello, Redis!": Stores the string "Hello, Redis!" with the key mykey.
• EXPIRE mykey 10: Sets a timeout of 10 seconds on mykey. After 10 seconds, mykey will be deleted.

1. Set a key name with the value "Alice".
2. Retrieve the value of the key name.
3. Delete the key name.
4. Check if the key name exists.

Solution:

1. Set a key score with the value 5.
2. Increment the value of score by 1.
3. Decrement the value of score by 1.

Solution:

1. Set multiple keys key1 and key2 with values "value1" and "value2".
2. Retrieve the values of key1 and key2.

Solution:

• Mistake: Forgetting to use quotes for string values.

  • Tip: Always use quotes for string values to avoid syntax errors.

• Mistake: Using GET on a non-existent key.

  • Tip: Use EXISTS to check if a key exists before using GET.

In this section, we covered the basic commands in Redis, including setting and getting values, deleting keys, checking key existence, and more. These commands form the foundation for interacting with Redis and are essential for performing basic operations. In the next section, we will delve into more advanced commands and operations.