LIMITing an SQL JOIN

SELECT expense.*, transaction.* FROM expense
INNER JOIN transaction ON expense_id = transaction_expense_id

select * from expense, transaction where expense_id = transaction_expense_id

select * from expense, transaction where expense_id = transaction_expense_id and
  expense_id in (select expense_id from expense limit 1)

select * from (select id from expense order by WHATEVER limit 1) as t1, transaction where expense_id=transaction_expense_id;

SELECT
    expense.*, transaction.*, user.*
FROM
    (SELECT * FROM expense WHERE ...) AS expense
INNER JOIN
    transaction ON expense_id = transaction_expense_id

expenses = SELECT * FROM expense ... LIMIT x
foreach expenses as expense
    expense.transactions = SELECT * FROM transacion WHERE transaction_expense_id = expense.expense_id