Using Multiple Summary Queries

SELECT 'After 1/1/2018' AS selection_date,

COUNT(*) AS number_of_invoices,

ROUND(AVG(invoice_total), 2) AS avg_invoice_amt,

SUM(invoice_total) AS total_invoice_amt

FROM invoices

WHERE invoice_date > '2018-01-01'

Statically Label the Row with a String

Count the number of Records

Calculate the Average invoice amount and Round it to 2 places

Add up all the invoice totals

The Output for this Query