List the top 10 customers by total gross sales. List customers' first and last name and total gross sales.
SELECT T1.first_name ,  T1.last_name ,  SUM(T2.total) FROM customers AS T1 JOIN invoices AS T2 ON T2.customer_id  =  T1.id GROUP BY T1.id ORDER BY SUM(T2.total) DESC LIMIT 10;
SELECT T1.first_name ,  T1.last_name ,  SUM(T2.total) FROM customers AS T1 JOIN invoices AS T2 ON T2.customer_id  =  T1.id GROUP BY T1.id ORDER BY SUM(T2.total) DESC LIMIT 10;
[{'first_name': 'Helena', 'last_name': 'Holý', 'SUM(T2.total)': 49.620000000000005}, {'first_name': 'Richard', 'last_name': 'Cunningham', 'SUM(T2.total)': 47.620000000000005}, {'first_name': 'Luis', 'last_name': 'Rojas', 'SUM(T2.total)': 46.62}, {'first_name': 'Ladislav', 'last_name': 'Kovács', 'SUM(T2.total)': 45.62}, {'first_name': 'Hugh', 'last_name': "O'Reilly", 'SUM(T2.total)': 45.62}, {'first_name': 'Julia', 'last_name': 'Barnett', 'SUM(T2.total)': 43.620000000000005}, {'first_name': 'Frank', 'last_name': 'Ralston', 'SUM(T2.total)': 43.62}, {'first_name': 'Fynn', 'last_name': 'Zimmermann', 'SUM(T2.total)': 43.62}, {'first_name': 'Astrid', 'last_name': 'Gruber', 'SUM(T2.total)': 42.62}, {'first_name': 'Victor', 'last_name': 'Stevens', 'SUM(T2.total)': 42.62}]