SELECT
    EMP_CODE AS CODE,
    EMP_LAST_NAME AS SURNAME,
    EMP_FIRST_NAME AS NAME
FROM
    EMP
WHERE
    VALID_FLG = '1'
    AND REPLACE(EMP_LAST_NAME || EMP_FIRST_NAME, ' ','') IN(
        -- 重複している(2回以上登場する)姓名を抽出
        SELECT
            REPLACE(EMP_LAST_NAME || EMP_FIRST_NAME, ' ','') AS N
        FROM
            EMP
        WHERE
            VALID_FLG = '1'
        GROUP BY
            N
        HAVING
            COUNT(*) >= 2
    )
ORDER BY
    REPLACE(EMP_LAST_NAME || EMP_FIRST_NAME, ' ',''),
    CODE
;