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 Ref_Transaction_Types ( transaction_type_description VARCHAR, transaction_type_code VARCHAR )

### Question ###
Show the description of transaction type with code 'PUR'.

### Accurate SQL ###

SELECT transaction_type_description FROM Ref_Transaction_Types WHERE transaction_type_code = "PUR"