Show the account id for each transaction.
select account_id from financial_transactions
Also show the account name for each.
select t2.account_name, t1.account_id from financial_transactions as t1 join accounts as t2 on t1.account_id = t2.account_id
For each account, show the number of transactions.
select t2.account_name, t1.account_id, count(*) from financial_transactions as t1 join accounts as t2 on t1.account_id = t2.account_id group by t1.account_id