Database: e_commerce
Question: What are the dates and ids of the invoices that are related to at least 2 shipments?
SQL:
SELECT T1.invoice_date ,  T1.invoice_number FROM Invoices AS T1 JOIN Shipments AS T2 ON T1.invoice_number  =  T2.invoice_number GROUP BY T1.invoice_number HAVING count(*)  >=  2