Que tal Carlos, soy nuevo en este foro, espero este query sea lo que necesitas:
-- TABLA "RELACIÓN DE FACTURAS - ÓRDENES DE COMPRA
DECLARE @FACT AS TABLE(DocNum INT, NumAtCard VARCHAR(100), DocDate DATE, BaseEntry INT, BaseType INT)
-- VISTA "FACTURAS - ÓRDENES DE COMPRA"
INSERT INTO @FACT
-- FACTURA - ÓRDEN DE COMPRA
SELECT DISTINCT T1.DocNum, T1.NumAtCard, T1.DocDate, T0.BaseEntry, T0.BaseType
FROM PCH1 T0
INNER JOIN OPCH T1 ON T0.DocEntry = T1.DocEntry
WHERE T0.BaseType = 22
UNION ALL
-- FACTURA - ENTRADA - ÓRDEN DE COMPRA
SELECT DISTINCT T1.DocNum, T1.NumAtCard, T1.DocDate, T2.BaseEntry, T2.BaseType
FROM PCH1 T0
INNER JOIN OPCH T1 ON T0.DocEntry = T1.DocEntry
INNER JOIN PDN1 T2 ON T0.BaseEntry = T2.DocEntry AND T0.BaseType = T2.ObjType
WHERE T2.BaseType = 22
-- VISTA PRINCIPAL
SELECT DISTINCT
-- DATOS DE ÓRDENES DE COMPRA
T0.DocNum [Doc SAP] ,T0.NumAtCard [Referencia] ,T0.DocDate [Fecha],
-- DATOS DE FACTURAS DE PROVEEDOR
T1.DocNum [Fact. SAP], T1.NumAtCard [Referencia], T1.DocDate [Fecha]
FROM OPOR T0
LEFT JOIN @FACT T1 ON T0.DocEntry = T1.BaseEntry AND T0.ObjType = T1.BaseType
WHERE T0.DocDate >= [%0] AND T0.DocDate <= [%1]
ORDER BY 1
Saludos,