https://www.youtube.com/watch?v=Fin8lZIWep4

CREATE TABLE user_content (content_id INT PRIMARY KEY,customer_id INT,content_type VARCHAR(50),content_text VARCHAR(255));

INSERT INTO
user_content (content_id, customer_id, content_type, content_text) 
VALUES
(1, 2, 'comment', 'hello world! this is a TEST.')
,(2, 8, 'comment', 'what a great day')
,(3, 4, 'comment', 'WELCOME to the event.')
,(4, 2, 'comment', 'e-commerce is booming.')
,(5, 6, 'comment', 'Python is fun!!')
,(6, 6, 'review', '123 numbers in text.')
,(7, 10, 'review', 'special chars: @#$%^&*()')
,(8, 4, 'comment', 'multiple CAPITALS here.')
,(9, 6, 'review', 'sentence. and ANOTHER sentence!'),(10, 2, 'post', 'goodBYE!')

CONCAT()
LEFT()
UPPER()/LOWER()

select * 
	,CONCAT(UPPER(LEFT(content_text,1)) ,
    LOWER(SUBSTRING(content_text,2,LENGTH(content_text)))) AS Modified_text
from uc;