SAP Business One query to retrieve the top customers based on their total sales amount

 SELECT 

    T0.CardCode, 

    T0.CardName, 

    SUM(T1.LineTotal) AS 'Total Sales'

FROM 

    OCRD T0

    INNER JOIN OINV T1 ON T0.CardCode = T1.CardCode

WHERE 

    T1.DocStatus = 'C' 

GROUP BY 

    T0.CardCode, 

    T0.CardName

ORDER BY 

    SUM(T1.LineTotal) DESC