SELECT * FROM(
SELECT *,ROW_NUMBER() OVER(PARTITION BY a.claimno ORDER BY b.financiancedate DESC) number FROM
(SELECT * FROM database1.table1 WHERE dt = "20200110")a
LEFT JOIN
(SELECT * FROM database2.table2 WHERE dt = "20200210")b
ON a.baseid = b.baseid)c
WHERE c.number = "1";