ステップ 3: ビューを作成して最終レポートテーブルにロードする

CREATE VIEW employee_view AS

SELECT t1.* FROM

 

(SELECT * FROM employee

    UNION ALL

    SELECT * FROM employee_extnl) t1

JOIN

    (SELECT employeeid, max(record_datetime) max_modified FROM

        (SELECT * FROM employee

        UNION ALL

        SELECT * FROM employee_extnl) t2

    GROUP BY employeeid) s

ON t1.employeeid = s.employeeid AND t1.record_datetime = s.max_modified;