SELECT count(*) FROM customers AS T1 JOIN invoices AS T2 ON T1.id = T2.customer_id WHERE T1.first_name = "Lucas" AND T1.last_name = "Mancini";
How many orders does Lucas Mancini has?
SELECT count ( * ) 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 count ( * ) from customers as t1 join invoices as t2 on t1 . id = t2 . customer_id where t1 . first_name = value and t1 . last_name = value
How many orders does Lucas Mancini has ?