Practise reading data with SELECT, choosing columns, calculating values, and filtering rows with WHERE.
All problems use this employees table:
Return the name and city of every employee.
List the two columns after SELECT, separated by a comma.
SELECT name, city
FROM employees;name | city
------+----------
Asha | Mumbai
Ravi | Bengaluru
Meera | Pune
John | Mumbai
Priya | DelhiThe salary column is a yearly figure. Return each employee's name and their monthly salary as a column called monthly_salary.
Divide by 12 and name the result with AS.
SELECT name, salary / 12 AS monthly_salary
FROM employees;If both values are integers, some databases (PostgreSQL, SQL Server, SQLite) perform integer division and drop the decimals. Write salary / 12.0 to keep them.
Return the name and salary of employees who live in Mumbai or Delhi.
Use IN ('Mumbai', 'Delhi'), or two conditions joined with OR.
SELECT name, salary
FROM employees
WHERE city IN ('Mumbai', 'Delhi');name | salary
------+-------
Asha | 52000
John | 46000
Priya | 61000Return the names of employees whose salary is between 50,000 and 80,000 (inclusive) and whose name ends with "a".
Combine BETWEEN and LIKE '%a' with AND.
SELECT name
FROM employees
WHERE salary BETWEEN 50000 AND 80000
AND name LIKE '%a';name
-----
Asha
PriyaMeera also ends with "a", but her salary of 81,000 is outside the range. Ravi is in the range but his name ends with "i".