gunshi-project-ss/src/main/resources/mapper/StPptnRMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.gunshi.project.xyt.mapper.StPptnRMapper">

    <select id="getStcdLastPptnData" resultType="com.gunshi.project.xyt.model.StPptnR">
        SELECT stb.stcd,
               r.tm stm
        FROM public.st_stbprp_b stb
                 LEFT JOIN (SELECT *
                            FROM (SELECT *, ROW_NUMBER() OVER ( PARTITION BY stcd ORDER BY tm DESC ) AS rn FROM public.st_pptn_r) subquery
                            WHERE subquery.rn = 1) r ON stb.stcd = r.stcd
        WHERE stb.source = 'SK'
    </select>
</mapper>