SELECT T2.InvoiceDate FROM CUSTOMER AS T1 JOIN INVOICE AS T2 ON T1.CustomerId  =  T2.CustomerId WHERE T1.FirstName  =  "Astrid" AND LastName  =  "Gruber"
What are the invoice dates for customers with the first name Astrid and the last name Gruber?
SELECT T2.InvoiceDate FROM CUSTOMER AS T1 JOIN INVOICE AS T2 ON T1.CustomerId = T2.CustomerId WHERE T1.FirstName = `` Astrid '' AND LastName = `` Gruber ''
select t2 . invoicedate from customer as t1 join invoice as t2 on t1 . customerid = t2 . customerid where t1 . firstname = value and lastname = value
What are the invoice dates for customers with the first name Astrid and the last name Gruber ?