Record the problems encountered in learning SSM framework 3
Exception Reporting
Message Request processing failed; nested exception is org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.type.TypeException: Could not set parameters for mapping: ParameterMapping{property=‘id’, mode=IN, javaType=class java.lang.Integer, jdbcType=null, numericScale=null, resultMapId=‘null’, jdbcTypeName=‘null’, expression=‘null’}. Cause: org.apache.ibatis.type.TypeException: Error setting non null for parameter #3 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 (3 > number of parameters, which is 2).
Description The server encountered an unexpected condition that prevented it from completing the request.
The problem occurs mainly in the mapper.xml file and can be due to several reasons.
1. two #’s are written together and will be identified incorrectly (my error)

<update id="updateById" parameterType="main.java.com.dy.domain.News">
        update news
        <set>
            <include refid="News_update"/>
        </set>
        where id=##{id}
    </update>

2. JavaEE comments appear inside/**/

<update id="updateById" parameterType="main.java.com.dy.domain.News">
        update news
        <set> /*  */
            <include refid="News_update"/>
        </set>
        where id=#{id}
    </update>

3. #{id} covered with quotation marks

<update id="updateById" parameterType="main.java.com.dy.domain.News">
        update news
        <set>
            <include refid="News_update"/>
        </set>
        where id='#{id}'
    </update>

All the above detailed errors may lead to errors in the execution of SQL statements, so we should be as careful as possible in the future development process.