SQL Query Basics.sql

-- Write a query to display the names of those students 
--that are between the ages of 18 and 20.
SELECT student_name
FROM students 
WHERE age BETWEEN 18 AND 20;

--Write a query to display all of those students that 
--contain the letters "ch" in their name or their name 
--ends with the letters "nd".

SELECT student_name
FROM students 
WHERE student_name LIKE '%ch%' 
OR student_name LIKE '%nd';

--Write a query to display the name of those students 
--that have the letters "ae" or "ph" in their name and 
--are NOT 19 years old.

SELECT student_name
FROM students 
WHERE (student_name LIKE '%ae%' 
OR student_name LIKE '%ph%')
AND age != 19; 

SELECT *
FROM students

--Write a query that lists the names of students 
--sorted by their age from largest to smallest.

SELECT student_name 
FROM students
ORDER BY age DESC;

--Write a query that displays the names and ages 
--of the top 4 oldest students.

SELECT student_name, age
FROM students
ORDER BY age DESC
FETCH FIRST 4 ROWS ONLY;

"""The student must not be older than age 20 
if their student_no is either between 3 and 
5 or their student_no is 7. Your query should 
also return students older than age 20 but in 
that case they must have a student_no that is 
at least 4."""

SELECT * 
FROM students
WHERE age <= 20
AND (student_no between 3 AND 5 OR student_no =7)
OR (age > 20 and student_no >= 4);


SELECT SUBSTRING('THIS IS TEST DATA' FROM 9) test_data_extracted