Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE TRANSACTIONS (transaction_type_code VARCHAR)
### Question:
Show the transaction type code that occurs the fewest times.
### Answer:
SELECT transaction_type_code FROM TRANSACTIONS GROUP BY transaction_type_code ORDER BY COUNT(*) LIMIT 1