Mybatis如何按顺序查询出对应的数据字段

目录

mybatis按顺序查询出对应的数据字段

今天遇到一个问题，就是写xml文件时，返回的顺序始终不一致，无论我sql语句写的如何好，前端接收到的数据都是乱的。终于，我发现到了醉翁亭记注音版原因。

原来我的查询返回resulttype = “map” ， 也就是这个map, 打乱了顺序。

因为map 并不保证存入取出顺序一致, 因此，打乱顺序可想而知了。

解决方法

resulttype = “map” 改为 resulttype=”java.util.linkedhashmap” 。

介绍：返回为linkedhashmap时，表中存储的null值并不会存入map中。

mybatis基本查询、条件查询、查询排序

<?xml version="1.0" encoding="utf-8"?><!doctype mapper public "-//mybatis.org//dtd mapper 3.0//en"        "http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="com.inspur.analysis.tool.ontology.linktype.dao.linktypemapper">    <resultmap type="com.inspur.analysis.tool.ontology.linktype.data.linktype" id="linktype">        <id property="linkuri" column="link_uri"/>        <result property="urihash" column="uri_hash"/>        <result property="batypeuri" column="ba_type_uri"/>        <result property="linklabel" column="link_label"/>        <result property="isasymmetrical" column="is_asymmetrical"/>        <result property="alia" column="alia"/>        <result property="pcname" column="p_c_name"/>        <result property="pcalia" column="p_c_alia"/>        <result property="cpname" column="c_p_name"/>        <result property="cpalia" column="c_p_alia"/>        <result property="detailiconuri" column="detail_icon_uri"/>        <result property="detailicon" column="detail_icon"/>        <result property="edgeiconuri" column="edge_icon_uri"/>        <result property="edgeicon" column="edge_icon"/>        <result property="issys" column="is_sys"/>        <result property="note" column="note"/>        <result property="creatorid" column="creator_id"/>        <result property="createtime" column="create_time"/>        <result property="editorid" column="editor_id"/>        <result property="edittime" column="edit_time"/>        <result property="scn" column="scn"/>    </resultmap>    <lect id="existlinktypeuri" parametertype="string"            resultmap="linktype">        lect * from od_link_t杞人忧天原文ype        where link_uri = #{linkuri}    </lect>    <lect id="isrootlinktype" parametertype="string"            resulttype="int">        lect exists(lect link_uri from od_link_type                                progresd      where link_uri=ba_type_uri and link_uri=#{linkuri})    </lect>    <lect id="deleterootlinktype" parametertype="string">        delete from od_link_type where ba_type_uri=#{batypeuri}    </lect>    <lect id="getrootlinktypelist"  resultmap="linktype">        lect * from od_link_type        where link_uri =  ba_type_uri    </lect>    <lect id="getalllinktypelistbyparent" parametertype="java.util.map"            resultmap="linktype">        lect * from od_link_type        <where>            link_uri != ba_type_uri            <if test="batypeuri != null">              and ba_type_uri=#{batypeuri}            </if>        </where>        <if test="orderfield != null" >         order by            <choo>                    <when test="orderfield == 'linkuri'">                鸿门宴课文        link_ur2020感动中国十大人物观后感i ${orderdir}                 </when>                   <when test="orderfield == 'linklabel'">                        link_label ${orderdir}                 </when>                   <otherwi>                   ba_type_uri ${orderdir}                </otherwi>             </choo>            </if>    </lect>    <lect id="getlinktypelistbycondition" parametertype="java.util.map"  resultmap="linktype">        lect * from od_link_type        <where>            link_uri != ba_type_uri            <if test="linkuri != null">               and link_uri like '%${linkuri}%'            </if>            <if test="linklabel != null">                and link_label like '%${linklabel}%'            </if>            <if test="batypeuri != null">                and ba_type_uri=#{batypeuri}            </if>        </where>      <if test="orderfield != null" >         order by            <choo>                    <when test="orderfield == 'linkuri'">                        link_uri ${orderdir}                 </when>                   <when test="orderfield == 'linklabel'">                        link_label ${orderdir}                 </when>                   <otherwi>                   ba_type_uri ${orderdir}                </otherwi>             </choo>            </if>    </lect></mapper>

以上为个人经验，希望能给大家一个参考，也希望大家多多支持www.887551.com。