mybatis 配置返回集合collection时只有一条记录

mybatis 配置返回集合collection时只有一条记录"/>

mybatis 配置返回集合collection时只有一条记录

查询语句配置如下：

<select id="selectCustomerList" resultMap="CustomerDtoMap" parameterType="map">select * from(select <include refid="AliasCustomerColumnList"/>from customer c) cleft join display_venue_reserve dvron c.c_customer_id = dvr.customer_id where 1=1<if test="customerMgrId != null">and c.c_customer_mgr_id = #{customerMgrId}</if><if test="status != null">and dvr.status = #{status}</if>
</select>

resultMap配置如下

<resultMap id="CustomerDtoMap" type="com.al.ec.showroom.dto.customer.CustomerDto" extends="AliasBaseResultMap"><collection property="displayVenueReserveDtoList" ofType="com.al.ec.showroom.dto.display.DisplayVenueReserveDto"><association property="displayVenueReserve" column="VENUE_RESERVE_ID" javaType="com.al.ec.showroom.model.display.DisplayVenueReserve"resultMap="com.al.ec.showroom.mapper.display.DisplayVenueReserveMapper.BaseResultMap"></association></collection></resultMap>

查询出结果如下：

只有一条记录，但是数据库直接执行语句是有多条记录的

经过很多轮的改代码研究，发现是因为

<collection property="displayVenueReserveDtoList" ofType="com.al.ec.showroom.dto.display.DisplayVenueReserveDto"><association property="displayVenueReserve" column="VENUE_RESERVE_ID" javaType="com.al.ec.showroom.model.display.DisplayVenueReserve"resultMap="com.al.ec.showroom.mapper.display.DisplayVenueReserveMapper.BaseResultMap"></association></collection>

需要在collection节点下添加

<id column="dvr_VENUE_RESERVE_ID" property="venueReserveId" jdbcType="DECIMAL"></id>

更改后代码如下

<resultMap id="CustomerDtoMap" type="com.al.ec.showroom.dto.customer.CustomerDto" extends="AliasBaseResultMap"><collection property="displayVenueReserveDtoList" ofType="com.al.ec.showroom.dto.display.DisplayVenueReserveDto"><id column="VENUE_RESERVE_ID" property="venueReserveId" jdbcType="DECIMAL"></id><association property="displayVenueReserve" column="VENUE_RESERVE_ID" javaType="com.al.ec.showroom.model.display.DisplayVenueReserve"resultMap="com.al.ec.showroom.mapper.display.DisplayVenueReserveMapper.AliasBaseResultMap"></association></collection></resultMap>

一直以为<association>节点有column属性就可以作为主键就可以了。。。。原来是需要在<collection>下添加id子节点

查询结果如下

但是对于这样配置的原理还不是很了解，如果知道的大神希望能在评论里给出回复，感谢

小白，刚接触mybatis不久，记录在此，谨记于心~~

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