用习惯了Hibernate，再换成Mybatis总会遇到一些变态问题，正如下面的错误提示，用mybatis查询时，传入一个字符串传参数，且进行判断时，会报 错误
There is no getter for property named 'moduleCode' in 'class java.lang.String
Dao层调用方式
/*
* Dao层查询
*/
@Override
public List<CityFace> findCityFaceByCondition(String eqDate) {
return sqlSession.selectList(CityFace.class.getName()+"_Mapper.findCityFaceByCondition",eqDate);
}
常见的错误写法：XML映射Sql
<select id="findCityFaceByCondition" parameterType="String" resultType="CityFace">
select * from (select unitname, to_char(rdate,'yyyy-MM') rdate,analysistype, scope from CITYSCAPEANALYSIS)
pivot (sum(scope) for analysistype in ('ESScope' esscope, 'EOScope' eoscope,'GCScope' gcscope, 'CScope' cscope))
<if test='eqDate!=""'>
where rdate = #{eqDate}
</if>
</select>
需要修改成：
<select id="findCityFaceByCondition" parameterType="String" resultType="CityFace">
select * from (select unitname, to_char(rdate,'yyyy-MM') rdate,analysistype, scope from CITYSCAPEANALYSIS)
pivot (sum(scope) for analysistype in ('ESScope' esscope, 'EOScope' eoscope,'GCScope' gcscope, 'CScope' cscope))
<if test='_parameter!=""'>
where rdate = #{_parameter}
</if>
</select>
不管你的参数是什么，都不管你的参数是什么，都要改成"_parameter"，但是ID就不用改就行
Java调用ID示例
@Override
public Visitlogs findVisitlogsById(int id) {
return sqlSession.selectOne(Visitlogs.class.getName()+"_Mapper.findVisitlogsById", id);
}
xml映射
<!-- 根据id查询用户 -->
<select id="findVisitlogsById" parameterType="int" resultMap="resultVisitlogs">
select * from visitlogs where id=#{id}
</select>
上面说的是String单个值，如果是多个值就可以使用map对象和Bean类对象进行封装，然后就可以使用常用的方式接收了，比如下面的案例
Java调用Map示例
@Override
public AppUser loginUser(String userName, String password) {
Map<String, String> map = new HashMap<String, String>();
map.put("name", userName);
map.put("password", password);
return sqlSession.selectOne(AppUser.class.getName()+"_Mapper.loginUser", map);
}
xml映射
<!-- 登录用户 -->
<select id="loginUser" parameterType="map" resultType="AppUser">
select * from app_user where name=#{name} and password=#{password}
</select>
Java调用Bean类示例
@Override
public AppUser loginUser(String userName, String password) {
AppUser user = new AppUser();
user.setName(userName);
user.setPassword(password);
return sqlSession.selectOne(AppUser.class.getName()+"_Mapper.loginUser", user);
}
xml映射
<!-- 登录用户 -->
<select id="loginUser" parameterType="AppUser" resultType="AppUser">
select * from app_user where name=#{name} and password=#{password}
</select>
