mybatis关联查询一对多问题解决，将表中对应的多条数据以list形式存储

<?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="GmsMapLayerMapper"><insert id="save" useGeneratedKeys="true" keyProperty="id">insertinto gms_map_layer (    map_id,    layer_id,    name,    has_index,    datasource_id,    display_order,    geo_type,    visible,    create_time,    update_time,    data_layer_name,    editable,    category,    sub_category) values (    #{mapId},    #{layerId},    #{name},    #{hasIndex},    #{datasourceId},    #{displayOrder},    #{geoType},    #{visible},    #{createTime},    #{updateTime},    #{dataLayerName},    #{editable},    #{category},    #{subCategory})</insert><select id="query" resultMap="resultMap">select * from gms_map_layer<where>1=1    <if test="id != null">    and  id=#{id}    </if>    <if test="mapId != null">    and  map_id=#{mapId}    </if>    <if test="layerId != null">    and  layer_id=#{layerId}    </if>    <if test="name != null and name != ''">    and  name=#{name}    </if>    <if test="hasIndex != null">    and  has_index=#{hasIndex}    </if>    <if test="datasourceId != null">    and  datasource_id=#{datasourceId}    </if>    <if test="displayOrder != null">    and  display_order=#{displayOrder}    </if>    <if test="visible != null and visible != ''">    and  visible=#{visible}    </if>    <if test="geoType != null">    and  geo_type=#{geoType}    </if>    <if test="createTime != null">    and  create_time=#{createTime}    </if>    <if test="updateTime != null">    and  update_time=#{updateTime}    </if>    <if test="dataLayerName != null and dataLayerName != ''">    and  data_layer_name=#{dataLayerName}    </if>    <if test="editable != null">    and  editable=#{editable}    </if>    <if test="category != null and category != ''">    and  category=#{category}    </if>    <if test="subCategory != null and subCategory != ''">    and  sub_category=#{subCategory}    </if></where>order by display_order asc</select>    <select id="queryByMapId" resultMap="OnlyLayerResultMap" parameterType="long">select * from gms_map_layerwhere map_id=#{mapId}</select><select id="queryForTreeByMapId" resultMap="treeItemResultMap" parameterType="long">select l.id,l.name,'C_'||l.category as category,l.sub_category,min(s.min_zoom) as min_zoom,max(s.max_zoom) as max_zoomfrom gms_map_layer l,gms_map_layer_style swhere map_id=#{mapId} and l.id=s.map_layer_idand l.category not in ('40001') and l.name not in ('10001_176','10001_177','10001_178','20014_2')group by l.id,l.name,l.category,l.sub_categoryorder by l.category,l.sub_category</select><select id="queryByMapIdCategory" resultMap="OnlyLayerResultMap" >select * from gms_map_layerwhere map_id=#{mapId} and category=#{category}</select><select id="queryByIds" resultMap="resultMap">select * from gms_map_layerwhereid in<foreach item="item" index="index" collection="array" open="("separator="," close=")">#{item}</foreach></select><delete id="delete">delete from gms_map_layerwhere id = #{id}</delete><delete id="batchDelete">delete from gms_map_layerwhereid in<foreach item="item" index="index" collection="array" open="("separator="," close=")">#{item}</foreach></delete><update id="update">update gms_map_layer<set>    <if test="id != null">    id=#{id},    </if>    <if test="mapId != null">    map_id=#{mapId},    </if>    <if test="layerId != null">    layer_id=#{layerId},    </if>    <if test="name != null and name != ''">    name=#{name},    </if>    <if test="hasIndex != null">    has_index=#{hasIndex},    </if>    <if test="datasourceId != null">    datasource_id=#{datasourceId},    </if>    <if test="displayOrder != null">    display_order=#{displayOrder},    </if>    <if test="visible != null and visible != ''">    visible=#{visible},    </if>    <if test="geoType != null">    geo_type=#{geoType},    </if>    <if test="createTime != null">    create_time=#{createTime},    </if>    <if test="updateTime != null">    update_time=#{updateTime},    </if>    <if test="dataLayerName != null and dataLayerName != ''">    data_layer_name=#{dataLayerName},    </if>    <if test="editable != null">    editable=#{editable},    </if>    <if test="category != null and category != ''">    category=#{category},    </if>    <if test="subCategory != null and subCategory != ''">    sub_category=#{subCategory},    </if></set>where id=#{id}</update><resultMap type="GmsMapLayer" id="resultMap"><!-- 用id属性来映射主键字段 --><id property="id" column="id" />    <result property="mapId" column="map_id" />     <result property="layerId" column="layer_id" />     <result property="name" column="name" />     <result property="hasIndex" column="has_index" />     <result property="datasourceId" column="datasource_id" />     <result property="displayOrder" column="display_order" />     <result property="geoType" column="geo_type" />    <result property="visible" column="visible" />     <result property="createTime" column="create_time" />     <result property="updateTime" column="update_time" />    <result property="dataLayerName" column="data_layer_name" />     <result property="editable" column="editable" />     <result property="category" column="category" />    <result property="subCategory" column="sub_category" />    <collection property="styles" column="id" ofType="GmsMapLayerStyle" select="GmsMapLayerStyleMapper.queryByMapLayerId"/></resultMap><resultMap type="TreeItem" id="treeItemResultMap"><!-- 用id属性来映射主键字段 --><id property="id" column="id" />    <result property="pId" column="category" />     <result property="name" column="name" />     <result property="minZoom" column="min_zoom" />    <result property="maxZoom" column="max_zoom" />    <result property="subCategory" column="sub_category" /></resultMap><resultMap type="GmsMapLayer" id="OnlyLayerResultMap"><!-- 用id属性来映射主键字段 --><id property="id" column="id" />    <result property="mapId" column="map_id" />     <result property="layerId" column="layer_id" />     <result property="name" column="name" />     <result property="hasIndex" column="has_index" />     <result property="datasourceId" column="datasource_id" />     <result property="displayOrder" column="display_order" />     <result property="geoType" column="geo_type" />    <result property="visible" column="visible" />     <result property="mapId" column="map_id" />     <result property="updateTime" column="update_time" />    <result property="dataLayerName" column="data_layer_name" />     <result property="editable" column="editable" />     <result property="category" column="category" />    <result property="subCategory" column="sub_category" /></resultMap><select id="indexFieldsByModelid" resultType="string">select columnname from gds_meta_field where modelid=#{modelid} and dbindex=1;</select><select id="mapNameByLayerId" resultType="string">select gm.name gm_name    from gms_map_layer gl     join gms_map gm on  gl.map_id=gm.id where gl.layer_id=#{id};</select><select id="queryDetailByLayerid" resultMap="detailMap" parameterType="long">select gl.createdate gl_createdate,gl.id gl_id,gl.layername gl_name,gmf.id gmf_id,gmf.fieldtitle fieldTitle,gmf.fieldname fieldName,gmf.columnname columnName,gmf.fieldtype fieldType,gmf.fieldsize fieldSize,gmf.fieldinput fieldInput,gmf.fieldinputfilter fieldInputFilter,gmf.defaultvalue defaultValue,gmf.readonly readOnly,gmf.fieldorder fieldOrder,gmf.remark remark,gmf.dbindex dbindex,gmf.modelid modelid from gds_layer gl,gds_meta_field gmfwhere gl.modelid=gmf.modelid and gl.id=#{id};<!-- select gl.name,gm.name gm_name --><!--     from gms_map_layer gl  --><!--     join gms_map gm  --><!-- on  gl.map_id=gm.id  --><!-- where gl.layer_id=#{id}; --></select> <resultMap type="LayerDetail" id="detailMap"><result property="createDate" column="gl_createdate" /> <result property="name" column="gl_name" /><result property="id" column="gl_id" /><collection property="fields" ofType="GdsMetaField" javaType="list"><id property="id" column="gmf_id"/><result property="fieldTitle" column="fieldTitle"/><result property="modelId" column="modelid"/><result property="fieldName" column="fieldName"/><result property="columnName" column="columnName"/><result property="fieldType" column="fieldType"/><result property="fieldSize" column="fieldSize"/><result property="fieldInput" column="fieldInput"/><result property="fieldInputFilter" column="fieldInputFilter"/><result property="defaultValue" column="defaultValue"/><result property="readOnly" column="readOnly"/><result property="fieldOrder" column="fieldOrder"/><result property="remark" column="remark"/><result property="dbindex" column="dbindex"/></collection><collection property="indexFields" column="modelid=modelid" ofType="string" javaType="list" select="indexFieldsByModelid"><result property="columnname" column="columnname"/></collection><collection property="maps" ofType="String" column="id=gl_id" javaType="list" select="mapNameByLayerId" ><result property="name" column="gm_name"/></collection></resultMap></mapper>