human
Schema:
Investors (investor_id, Investor_details)
Lots (lot_id, investor_id, lot_details)
Ref_Transaction_Types (transaction_type_code, transaction_type_description)
Transactions (transaction_id, investor_id, transaction_type_code, date_of_transaction, amount_of_transaction, share_count, other_details)
Sales (sales_transaction_id, sales_details)
Purchases (purchase_transaction_id, purchase_details)
Transactions_Lots (transaction_id, lot_id)
Please answer with SQL.
assistant
Sure, I understand.
human
Please show the description of the transaction type 'SALE'.
assistant
SELECT transaction_type_description FROM Ref_Transaction_Types WHERE transaction_type_code = 'SALE';
human
How many transaction types are there?
assistant
SELECT COUNT( * ) FROM Ref_Transaction_Types;
human
Among these transactions, which one occurs most frequently?
assistant
SELECT T1.transaction_type_code FROM Ref_Transaction_Types AS T1 JOIN TRANSACTIONS AS T2 ON T1.transaction_type_code = T2.transaction_type_code GROUP BY T1.transaction_type_code ORDER BY COUNT( * ) DESC LIMIT 1;
human
Show its description.
assistant
SELECT T1.transaction_type_description FROM Ref_Transaction_Types AS T1 JOIN TRANSACTIONS AS T2 ON T1.transaction_type_code = T2.transaction_type_code GROUP BY T1.transaction_type_code ORDER BY COUNT( * ) DESC LIMIT 1 ;