Could not set parameters for mapping in Mybatis when using Springboot framework-CodePudding

I am a new starter of Java web and I have tried many ways in Stack Overflow to solve the problem but failed. Could you help me?

The interface in my code is:

public List<Answer> selectAnswerByUser(@Param("user") User user,  @Param("id") Integer id);

where Answer and User are two classes I have defined.

The Mapper is:

<select id="selectAnswerByUser" parameterType="java.util.Map" resultType="Answer">
    select * from answer where exercise_id=#{id} and user_email='#{user.email}'
</select>

where email is a variable of Class User.

And it throws:

nested exception is org.apache.ibatis.type.TypeException: Could not set parameters for mapping: ParameterMapping{property='user.email', mode=IN, javaType=class java.lang.Object, jdbcType=null, numericScale=null, resultMapId='null', jdbcTypeName='null', expression='null'}. 
Cause: org.apache.ibatis.type.TypeException: Error setting non null for parameter #2 with JdbcType null . Try setting a different JdbcType for this parameter or a different configuration property. 
Cause: org.apache.ibatis.type.TypeException: Error setting non null for parameter #2 with JdbcType null . Try setting a different JdbcType for this parameter or a different configuration property. 
Cause: java.sql.SQLException: Parameter index out of range (2 > number of parameters, which is 1).

I have no idea about the exception.

CodePudding user response：

You are configuring the parameterType to parameterType="java.util.Map" when when you are passing two parameters User and Integer. Remove the parameterType="java.util.Map" and it should map the parameterTypes "automatically" based on the @Param annotation. Or try with parameterType="map"