#### 常规修改 ``` <!-- 更新 --> <update id="update"> UPDATE reply_info <set> <if test="blogId!=null">blog_id=#{blogId},</if> <if test="commentId!=null">comment_id=#{commentId},</if> <if test="userId!=null">user_id=#{userId},</if> <if test="toUserId!=null">to_user_id=#{toUserId},</if> <if test="content!=null">content=#{content},</if> <if test="createTime!=null">create_time=#{createTime},</if> </set> WHERE id = #{id} </update> ``` #### 根据ID foreach修改 - 通用修改 Mapper接口 ``` //批量修改 - service要加事务回滚 Integer updateAll(@Param("param") Map<String,Object> param) throws Exception; Map构造数据 key为数据库字段，value为值 ``` Mapper.xml ``` <!—foreach修改 - 单条件--> <update id="updateAll" parameterType="java.util.HashMap"> UPDATE TABLE set <foreach item="value" index="key" collection="param" separator=","> ${key} = #{value} </foreach> WHERE ID = #{param.id} </update> <!—foreach修改 - 多条件--> <update id="setBsflagByFK" parameterType="hashmap"> update ${_tableName} set <foreach collection="data" index="colName" item="colValue" separator=",">${colName} = #{colValue}</foreach> where <foreach collection="_fk" index="colName" item="colValue" separator=" and ">${colName} = #{colValue}</foreach> </update> ```