Oracle Merge

MERGE INTO T_WEEKLYWORK_SUB
USING DUAL
ON ( WEEKLYWORK_HIST_ID = #{seq ,jdbcType=INTEGER} AND WORK_DIV = #{workDiv ,jdbcType=VARCHAR})
WHEN MATCHED THEN
UPDATE SET
      B_WEEK = #{bWeek ,jdbcType=VARCHAR}
    , N_WEEK = #{nWeek ,jdbcType=VARCHAR}
    , MOD_DATE = SYSDATE
    , MOD_ID = #{loginId ,jdbcType=VARCHAR}
WHEN NOT MATCHED THEN
INSERT (
      WEEKLYWORK_HIST_ID
    , WORK_DIV
    , N_WEEK
    , B_WEEK
    , REG_DATE
    , REG_ID
) VALUES (
      #{seq ,jdbcType=INTEGER}
    , #{workDiv ,jdbcType=VARCHAR}
    , #{nWeek ,jdbcType=VARCHAR}
    , #{bWeek ,jdbcType=VARCHAR}
    , SYSDATE
    , #{loginId ,jdbcType=VARCHAR}
)