Count Salary Categories | LeetCode

SELECT "Low Salary" AS category, 
COUNT(income) AS accounts_count 
FROM Accounts 
WHERE income < 20000 
UNION 
SELECT "Average Salary" AS category, 
COUNT(income) AS accounts_count 
FROM Accounts 
WHERE income >= 20000 AND income <= 50000 
UNION 
SELECT "High Salary" AS category, 
COUNT(income) AS accounts_count 
FROM Accounts 
WHERE income > 50000;