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 customers ( id VARCHAR, first_name VARCHAR, last_name VARCHAR )
TABLE: CREATE TABLE invoices ( total INTEGER, customer_id VARCHAR )

### Question ###
What is the total amount of money spent by Lucas Mancini?

### Accurate SQL ###

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"