Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE TRANSACTIONS ( transaction_type_code VARCHAR, amount_of_transaction INTEGER )

### Question ###
Show the average transaction amount for different transaction types.

### Accurate SQL ###

SELECT transaction_type_code, AVG(amount_of_transaction) FROM TRANSACTIONS GROUP BY transaction_type_code