mybatis出现了很奇怪的问题

 ### Error querying database.  Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'card_id' in 'field list'
### The error may exist in com/ershou/mapper/UserMapper.xml
### The error may involve com.ershou.mapper.UserMapper.selectByExample-Inline
### The error occurred while setting parameters
### SQL: select                 card_id, password, college, grade, sex, status, trueName, image         from user                    WHERE (  card_id = ?                                                                             and password = ? )
### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'card_id' in 'field list'
; bad SQL grammar []; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'card_id' in 'field list'] with root cause
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'card_id' in 'field list'

提示我的card_id 数据库不认识，但是我的数据库就是这样定义的啊
我用的也是generator自动生成的代码
CREATE TABLE user (
card_id varchar(20) NOT NULL,
password varchar(20) DEFAULT NULL,
college varchar(200) DEFAULT NULL,
grade varchar(200) DEFAULT NULL,
sex int(2) DEFAULT '1',
status int(2) DEFAULT '1',
trueName varchar(20) DEFAULT NULL,
image varchar(50) DEFAULT NULL,
PRIMARY KEY (card_id)
)

看一下mybatis的XXXMapper.xml文件

<select id="selectByExample" resultMap="BaseResultMap" parameterType="com.ershou.entity.UserExample" >
select
<if test="distinct" >
  distinct
</if>
<include refid="Base_Column_List" />
from user
<if test="_parameter != null" >
  <include refid="Example_Where_Clause" />
</if>
<if test="orderByClause != null" >
  order by ${orderByClause}
</if>

哪里出错了  见鬼了  求大神

这个是xml 的map映射

你需要在mpper.xml文件里映射实体以及实体类相对应的参数，如果以及做了映射关系看看是不是实体类的URL错了

需要在 resultMap标签里映射实体类

是不是字段前面多了空格?

解决方式有两种
1.同一二楼所说
2.在这个实体类中com.ershou.entity.UserExample 对应修改cardId 为card_id 请检查card_id字段是否和返回的字段名一致