判斷需要插入的資料是否存在，如果不存在就更新

<insert id="saveBatch" parameterType="java.util.List" >   MERGE INTO 表名 T   USING (  <foreach collection="list" item="item" index="index" separator="union" > SELECT SYS_GUID() AS CODE, #{item.createDate,jdbcType=VARCHAR} AS CREATE_DATE, #{item.createBy,jdbcType=VARCHAR} AS CREATE_BY, #{item.flagDel,jdbcType=CHAR} AS FLAG_DEL, #{item.flagDisplay,jdbcType=CHAR} AS FLAG_DISPLAY, #{item.sort,jdbcType=DECIMAL} AS SORT FROM DUAL </foreach>) T1   ON (T1./*判斷資料是否重複的欄位*/= T./*判斷資料是否重複的欄位*/ AND T1./*判斷資料是否重複的欄位*/ = T./*判斷資料是否重複的欄位*/) /*資料存在*/ WHEN MATCHED THEN UPDATE SET T./*需要更新的欄位*/=T1/*需要更新的欄位*/  /*資料不存在*/ WHEN NOT MATCHED THEN INSERT (CODE,CREATE_DATE,CREATE_BY,FLAG_DEL,FLAG_DISPLAY,SORT) VALUES   (T1.CODE,T1.CREATE_DATE,T1.CREATE_BY,T1.FLAG_DEL,T1.FLAG_DISPLAY,T1.SORT)  </insert>   

--轉載

<insert id="batchSave" parameterType="java.util.List">
    MERGE INTO RES_SCHOOL_CLUB t
    USING (
      <foreach collection="list" item="item" index="index" separator="union" >
        select #{item.id,jdbcType=VARCHAR} ID,
        #{item.clsSchoolId,jdbcType=VARCHAR} CLS_SCHOOL_ID,
        #{item.originSchoolId,jdbcType=VARCHAR} ORIGIN_SCHOOL_ID,
        #{item.resourceId,jdbcType=VARCHAR} RESOURCE_ID,
        #{item.clsClubId,jdbcType=VARCHAR} CLS_CLUB_ID,
        #{item.baseAreaId,jdbcType=VARCHAR} BASE_AREA_ID,
        #{item.createTime,jdbcType=TIMESTAMP} CREATE_TIME
        from dual
      </foreach
 
>) t1
    ON (t.CLS_SCHOOL_ID =  t1.CLS_SCHOOL_ID AND t.RESOURCE_ID = t1.RESOURCE_ID)
    WHEN MATCHED THEN
    UPDATE SET t.CREATE_TIME = t1.CREATE_TIME
    WHEN NOT MATCHED THEN
      INSERT(ID, CLS_SCHOOL_ID, ORIGIN_SCHOOL_ID, RESOURCE_ID, CLS_CLUB_ID, BASE_AREA_ID, CREATE_TIME)
      VALUES (t1.ID, t1.CLS_SCHOOL_ID, t1.ORIGIN_SCHOOL_ID, t1.RESOURCE_ID, t1.CLS_CLUB_ID, t1.BASE_AREA_ID, t1.CREATE_TIME)
</insert
 
>