SELECT sum(T2.total) FROM customers AS T1 JOIN invoices AS T2 ON T1.id = T2.customer_id WHERE T1.first_name = "Lucas" AND T1.last_name = "Mancini";
What is the total amount of money spent by Lucas Mancini?
SELECT sum ( T2.total ) FROM customers AS T1 JOIN invoices AS T2 ON T1.id = T2.customer_id WHERE T1.first_name = `` Lucas '' AND T1.last_name = `` Mancini '' ;
select sum ( t2 . total ) from customers as t1 join invoices as t2 on t1 . id = t2 . customer_id where t1 . first_name = value and t1 . last_name = value
What is the total amount of money spent by Lucas Mancini ?