**# NULL VALUES**

SELECT
     ISNULL("Hello!"); 
     -- Function to see if the values are true or false
     -- 0 = False / 1 = True
FROM bank.card;

SELECT
     sum(ISNULL(card_id))
     -- Summoning all the Null Values in the Column 'card_id'
FROM bank.card;

SELECT 
*
FROM bank.order
WHERE k_symbol is null;
-- using 'null' to see if there's null values in the 'k_symbol' column
WHERE k_symbol is null or k_symbol = ' ';
-- Checking Null Values in the column 'k_symbol' with spaces = ' ', in it
WHERE k_symbol is not null or  not k_symbol = ' ';