SELECT
    tenantName_tbl (c) as ten_name,
    c.name as c_name,
    COUNT (*)
FROM
    Pub.mtcustomer AS c
    INNER JOIN pub.mtorder AS o
    ON tenantId_tbl (c) = tenantId_tbl (o)
    AND c.custnum = o.custnum
    INNER JOIN pub.mtorderline AS ol
    ON tenantId_tbl (o) = tenantId_tbl (ol)
    AND o.ordernum = ol.ordernum
GROUP BY
    ten_name, c_name;