Hi Chris Cole,
Welcome to SAP B1 forum.
Please try this query too.
SELECT
T0.[DocNum], T0.[DocStatus], T0.[DocDate], T0.[DocDueDate], T0.[CardCode], T0.[CardName], T1.[ItemCode], T1.[Dscription], T1.[Quantity], T1.[Price], T1.[LineTotal]
FROM
OINV T0 INNER JOIN INV1 T1 ON T0.[DocEntry] = T1.[DocEntry]
WHERE
T0.[CardCode] =[%0] and T1.[ItemCode] =[%1]
Thank you