purchase_table.sql

/*
purchase table example

transaction_date        |    customer_id    |    purchase_price    |    category

2022-01-01                    customer_A           $10                  jewelry 

2022-01-02                    customer_A           $1                   t-shirts

...

2022-01-31                    customer_A           $5                   t-shirts

*/

SELECT transaction_date, purchase_price 
FROM purchase p
WHERE 
customer_id = <customer_A>
AND date > CURRENT_DATE - INTERVAL '30 DAYS'