how to use case when in sql code example

Example 1: sql case

Change query output depending on conditions.
Example: Returns users and their subscriptions, along with a new column
called activity_levels that makes a judgement based on the number of
subscriptions.
SELECT first_name, surname, subscriptions
CASE WHEN subscriptions > 10 THEN 'Very active'
WHEN Quantity BETWEEN 3 AND 10 THEN 'Active'
ELSE 'Inactive'
END AS activity_levels
FROM users;

Example 2: sql CASE

/*CASE statements are used to create different outputs and is 
  used by SQL as a way to handle if-then logic.*/
  
  SELECT column_name,
    CASE 
      WHEN condition THEN 'Result_1'
      WHEN condition THEN 'Result_2'
      ELSE 'Result_3'
    END
  FROM table_name;