<update id="batchUpdate">
        <foreach collection="list" item="item" open="begin" close=";end;" separator=";">
                UPDATE _表名
                <trim prefix="SET" suffixOverrides=",">
                    <if test="item._java类映射_字段名1 != null">
                        _字段名1 = #{item._java类映射_字段名1},
                    </if>
                   <if test="item._java类映射_字段名2 != null">
                        _字段名2 = #{item._java类映射_字段名2},
                    </if>
                    ...
                    <if test="item.updateBy != null">
                        update_by = #{item.updateBy},
                    </if>
                    <if test="item.updateTime != null">
                        update_time = #{item.updateTime}
                    </if>
                </trim>
                WHERE _修改的条件字段 = #{item._java类映射_字段名2,jdbcType=VARCHAR}
        </foreach>
    </update>