1 sql40

select
 
    id, name, phone_number
 
from
 
    contacts
 
where
 
    phone_number regexp '^[1-9][0-9]{2}-?[0-9]{3}-?[0-9]{4}$'

2 sql41

select
 
    profit_id,
 
    profit_date,
 
    profit,
 
    sum(profit) over(order by profit_date) as cumulative_profit
 
from
 
    daily_profits
 
order by
 
    profit_date asc

3 sql42

select
 
    id,
 
    value,
 
    abs(value) as absolute_value,
 
    ceil(value) as ceiling_value,
 
    floor(value) as floor_value,
 
    round(value, 1) as rounded_value
 
from
 
    numbers
 
order by
 
    id asc