<mapper namespace="com.example.EmployeeMapper">

    <!-- 更新employee_absent_resign_statistics表中的pre_work_date -->
    <update id="updatePreWorkDate">
        <![CDATA[
        UPDATE employee e1
        JOIN employee e2
            ON e2.statistics_date < e1.statistics_date
            AND e2.emplid = e1.emplid
        SET e1.pre_work_date = e2.statistics_date
        WHERE NOT EXISTS (
            SELECT 1
            FROM employee_absent_resign_statistics e3
            WHERE e3.statistics_date < e1.statistics_date
              AND e3.emplid = e1.emplid
              AND e3.statistics_date > e2.statistics_date
        )
        ]]>
    </update>

</mapper>