熟悉Ibatis的进,该如何解决

熟悉Ibatis的进
xmlResultName
当直接把查询结果映射成XML document时，属性xmlResultName的值等于XML document根元素的名称。例如：

XML code

<select id="getPerson" parameterClass=”int” resultClass="xml" xmlResultName=”person”>SELECT PER_ID as id,PER_FIRST_NAME as firstName,PER_LAST_NAME as lastName,PER_BIRTH_DATE as birthDate,PER_WEIGHT_KG as weightInKilograms,PER_HEIGHT_M as heightInMetersFROM PERSONWHERE PER_ID = #value#</select>

上面的查询结果将产生一个XML document，结构如下：

XML code

<person><id>1</id><firstName>Clinton</firstName><lastName>Begin</lastName><birthDate>1900-01-01</birthDate><weightInKilograms>89</weightInKilograms><heightInMeters>1.77</heightInMeters></person>

产生问题：如果id值为null的时候，查询结果产生的XML document中少了id那一列，这一列怎么才能出现在xml文件中？不能在sql中加case when 因为数据量很大，估计几10万的数据，字段可能有几百个。在不影响sql执行效率的前提下如何处理？跪求各位高手

XML code

<person><firstName>Clinton</firstName><lastName>Begin</lastName><birthDate>1900-01-01</birthDate><weightInKilograms>89</weightInKilograms><heightInMeters>1.77</heightInMeters></person>

[解决办法]
<select id="getPerson" parameterClass=”int” resultClass="xml" xmlResultName=”person”>
SELECT isnull(PER_ID,0) as id,
PER_FIRST_NAME as firstName,
PER_LAST_NAME as lastName,
PER_BIRTH_DATE as birthDate,
PER_WEIGHT_KG as weightInKilograms,
PER_HEIGHT_M as heightInMeters
FROM PERSON
WHERE PER_ID = #value#
</select>
[解决办法]
1楼已经提出了解决方案
[解决办法]
不改sql只能自己扩展ibatis了

查看更多 下一篇