方式一：case when then....

<!-- 批量更新拼音字段 -->
<update id="updatePinyin">
  UPDATE sys_region_continents
  SET C_NAME_PINYIN =
  <foreach collection="idNames" index="index" item="item"
           open="CASE ID" separator=" " close="END">
    WHEN #{item.id} THEN #{item.pinyin}
  </foreach>
  WHERE ID IN
  <foreach collection="idNames" index="index" item="item"
           open="(" separator="," close=")">
    #{item.id,jdbcType=BIGINT}
  </foreach>
</update>

方式二：insert into ... on duplicate key update

如果列不能为空或者没有默认值也许会报错：Field XXX doesn't have a default value，

<!-- 批量更新拼音字段 -->
<update id="updatePinyin">
  INSERT INTO sys_region(ID,C_NAME_PINYIN) VALUES
  <foreach collection="idNames" index="index" item="item" open="" separator="," close="">
    (#{item.id},#{item.pinyin})
  </foreach>
  ON DUPLICATE KEY UPDATE
  ID = VALUES(ID),
  C_NAME_PINYIN = VALUES(C_NAME_PINYIN)
</update>

方式三：replace into

这种方式只有替换的字段(示例中ID,C_NAME_PINYIN)有值，其余都会被清空掉

<!-- 批量更新拼音字段 -->
<update id="updatePinyin">
  REPLACE INTO sys_region_continents(ID,C_NAME_PINYIN) VALUES
  <foreach collection="idNames" index="index" item="item" open="" separator="," close="">
    (#{item.id},#{item.pinyin})
  </foreach>
</update>