需求：返回電話號碼列表，之前查詢多個字段時用Map作爲返回類型，現在單個字段列表用List。
最開始的寫法：
<select id="selectCellListByShopId" resultClass="List" parameterClass="java.lang.Long">
select P.TEL_PHONE
from SHOP_PHONE P
WHERE P.SHOP_ID =#shopId:BIGINT#
and P.IS_DEL = '0' and P.IS_ACTIVE = '1'
</select>
這樣查到的結果是[]列表，後來在老外的一篇文章上找到的解決方案，地址如下：
http://ibatis.10938.n7.nabble.com/return-simple-String-or-List-lt-String-gt-td17133.html
其中重點如下：
Tomas,
I am assuming that you have not read the developers guide and I just
giving things a go. You need to read the guide completely.
In this case Guy was saying that if your query only returns a string
then set the resultType to String. Then use the ibatis queryForList()
to compile your results into a List<String>.
Nathan
按照這個方案修改後的代碼如下：
<select id="selectCellListByShopId" resultClass="java.lang.String"
parameterClass="java.lang.Long">
select P.TEL_PHONE
from SHOP_PHONE P
WHERE P.SHOP_ID =#shopId:BIGINT#
and P.IS_DEL = '0' and P.IS_ACTIVE = '1'
</select>
Dao層通過queryForList()方法查詢出來即可。
小結：遇到這種問題的常用解決方案
1.查詢ibatis的官方文檔.
2.Google 關鍵字ibatis resultClass.