解決MyBatis查詢結果Map中值為null不儲存鍵值的問題
阿新 • • 發佈:2020-09-19
在日常開發中,查詢資料返回型別為map,資料庫中有些自動值為空,則返回的結果中沒有值為空的欄位,則如何顯示值為空的欄位呢?
1.xml檔案:
<resultMap id="userLoginInfo" type="map" > <result column="uuid" property="id" /> <result column="uuid2" property="uuid" /> <result column="account" property="phone" /> <result column="login_time"property="loginTime" /> <result column="token" property="token" /> <result column="data_progress" property="dataProgress" /> <result column="account_locked" property="accountLocked" /> <result column="is_delete" property="isDelete" /> <result column="nickname" property="nickname" /> <result column="user_head" property="userHead" /> </resultMap>
返回結果:
{accountLocked=false, loginTime=1480559610977, phone=18301413850, isDelete=false, dataProgress=0, nickname=, id=93cd68fcb95043febd28d6ad86666029, uuid=544dc45953e2dcc60e23ecccc52c578b, token=WT1Kgx}
發現返回結果Map中沒有user_head欄位,原來 user_head在資料庫中值為null,所以說資料庫中所有值為null的欄位在查詢接收resultMap時都不存在
解決方法:
1、在Mybatis_config.xml檔案中新增配置資訊:
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"> <configuration> <settings> <!--解決,查詢返回結果含null沒有對應欄位值問題--> <setting name="callSettersOnNulls" value="true"/> </settings> </configuration>
備註:注意xml檔案的頭部引入的是mybaties-3-config.dtd
測試結果:
{accountLocked=false, loginTime=1480559610977, userHead=null, phone=18301413850, isDelete=false, dataProgress=0, nickname=, id=93cd68fcb95043febd28d6ad86666029, uuid=544dc45953e2dcc60e23ecccc52c578b, token=WT1Kgx}
經測試,值為null的結果在map中存在
轉:https://blog.csdn.net/u014079773/article/details/66972454