-- Let's add a record to the table
INSERT INTO transactions (transaction_date, amount, fee) 
VALUES ('2018-09-24', 5454, '30');

-- Doublecheck the contents
SELECT *
FROM transactions;


In the video, you saw that type casts are a possible solution for data type issues. If you know that a certain column stores numbers as text, you can cast the column to a numeric form, i.e. to integer.

SELECT CAST(some_column AS integer)
FROM table;
Now, the some_column column is temporarily represented as integer instead of text, meaning that you can perform numeric calculations on the column.

-- Calculate the net amount as amount + fee
SELECT transaction_date, amount + CAST(fee AS integer) AS net_amount 
FROM transactions;