SQL / Banking / Transactions: Customers with more than one month's income

Question

Hi I have a table "transactions" with few bank transactions from different customers. In that table I also have the date for every transaction as well as their monthly average salary. Moreover, on a different table "account" I can get the bank account balances for few of these customers at any point in time.

I now have a request to work out which of these customers have more than one month's income and check for emergency savings / resilience. Any thoughts on how to go about this?

DDL for table transactions:

CREATE TABLE transactions (
customer_id uuid NOT NULL,
transaction_date varchar(10) NOT NULL,
transaction_id varchar NOT NULL,
transaction_amount numeric(10,2) NOT NULL,
description varchar NULL,
account_id uuid NOT NULL
)

DDL for table account:

CREATE TABLE account(
    customer_id uuid NOT NULL,
    account_id uuid NOT NULL,
    provider_id int8 NOT NULL,
    account_sub_type varchar NOT NULL,
    current_balance numeric(10,2) NULL
)

My CTE / query looks like the below so far:

WITH
over_one_income AS (
SELECT  customer_id, "month", "year", salary, transaction_amount, current_balance from 
    (
    SELECT ctf.customer_id
            ,date_part('month',ctf.date_key::date) as "month"
           ,date_part('year',ctf.date_key::date) as "year"
          ,round(sum(ctf.amount)/24/30,2) as transaction_amount 
          ,round(sm.yearly_net/12) as salary 
          ,sum(caf.current_balance) as current_balance

    from transactions ctf 
    join account caf 
    on ctf.customer_id = caf.customer_id and ctf.account_id = caf.account_id 
    join customer cf
    on cf.customer_id = caf.customer_id 
    join  salary_gross_to_net  sm
    on cf.annual_gross_salary= sm.yearly_gross
    group by ctf.customer_id
       ,date_part('month',ctf.date_key::date) 
       ,date_part('year',ctf.date_key::date)
       ,sm.yearly_net
   ) epc
   )
   
   select *  from over_one_income

The query above is outputting the below: