WITH target AS (
    SELECT
        e.EMP_CODE
    FROM
               EMP         e
    INNER JOIN EMP_INVALID i
            ON e.EMP_CODE = i.EMP_CODE
    WHERE
        e.VALID_FLG <> '1'
)
DELETE
FROM
    EMP
where
    EMP_CODE in (SELECT EMP_CODE FROM target)
;