Xml 结果映射Mybati不起作用
我有一个简单的映射器Xml 结果映射Mybati不起作用,xml,mybatis,Xml,Mybatis,我有一个简单的映射器 <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0 Powerhouse//EN" "http://mybatis.org/dtd/mybatis-3-Powerhouse-mapper.dtd"> <mapper namespace="nl.powerhouse.data.domain.CountryMa
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0 Powerhouse//EN" "http://mybatis.org/dtd/mybatis-3-Powerhouse-mapper.dtd">
<mapper namespace="nl.powerhouse.data.domain.CountryMapper">
<resultMap id="countryDsoMap" type="nl.powerhouse.domain.common.types.algemeen.Land">
<id column="land_id"/>
<association property="landId" columnPrefix="land_" column="id"/>
<association property="landcode" columnPrefix="land_" column="landcode"/>
<association property="landnaam" columnPrefix="land_" column="landnaam"/>
<association property="landnummer" columnPrefix="land_" column="landnummer"/>
<association property="handelsland" columnPrefix="land_" column="handelsland"/>
</resultMap>
<select id="findCountryByCode" resultMap="countryDsoMap">
select <includeColumns tableAlias="land" columnPrefix="land_" refid="nl.powerhouse.data.dao.algemeen.LandMapper.Base_Column_List"/>
from alg_t_land land
where landcode = #{countryCode}
</select>
但是,当我尝试使用它时,我得到以下错误:
org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException:
### Error querying database. Cause: java.lang.NullPointerException
### The error may exist in nl/powerhouse/data/domain/CountryMapper.xml
### The error may involve defaultParameterMap
### The error occurred while setting parameters
...
at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:75)
我知道查询正在运行,问题在于结果映射,有什么提示吗?问题在于您正在使用
:
结果图
结果–注入字段或JavaBean属性的正常结果
关联——一种复杂类型的关联;许多结果将会出现
进入这个
确切地说,映射不是复杂的类型关联,因此必须使用
而不是
您的结果图将是:
<resultMap id="countryDsoMap" type="nl.powerhouse.domain.common.types.algemeen.Land">
<id column="land_id"/>
<result property="landId" columnPrefix="land_" column="id"/>
<result property="landcode" columnPrefix="land_" column="landcode"/>
<result property="landnaam" columnPrefix="land_" column="landnaam"/>
<result property="landnummer" columnPrefix="land_" column="landnummer"/>
<result property="handelsland" columnPrefix="land_" column="handelsland"/>
</resultMap>
您的id:
没有属性属性
。我想你需要把
或者属性id如何在土地中调用我试过了,但没有成功,否则,你为什么要使用标签关联
?代替。示例:
结果有效,谢谢!
<resultMap id="countryDsoMap" type="nl.powerhouse.domain.common.types.algemeen.Land">
<id column="land_id"/>
<result property="landId" columnPrefix="land_" column="id"/>
<result property="landcode" columnPrefix="land_" column="landcode"/>
<result property="landnaam" columnPrefix="land_" column="landnaam"/>
<result property="landnummer" columnPrefix="land_" column="landnummer"/>
<result property="handelsland" columnPrefix="land_" column="handelsland"/>
</resultMap>