出的错误是：java.lang.IllegalArgumentException: argument type mismatch

hibernet的问题
出的错误是：java.lang.IllegalArgumentException: argument type mismatch
at org.yh.dlogic.FindCountDlogic.findCountByID(FindCountDlogic.java:39)
这个类FindCountDlogic的代码是

Java code

package org.yh.dlogic;

import java.util.ArrayList;
import java.util.List;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.cfg.Configuration;

public class FindCountDlogic {
    /**
     * session定义
     */
    private Session session =null;
    
    /**
     * 构造函数
     */
    public FindCountDlogic() {
        this.session =new Configuration().configure().
            buildSessionFactory().openSession();
    }
    
    public List findCountByID (String countId) {
        
        List countList = new ArrayList();

        StringBuffer sb = new StringBuffer("from Count");
        
        if (countId !=null && !"".equals(countId)) {
            sb.append(" where countid = "+countId);
        }
        
        String sql = sb.toString();
        
        Query query = this.session.createQuery(sql);
        
        [color=#FF0000]countList = query.list();[/color]

        return countList;    
    }

}

出错的就是红色的那行

count类的xml文件如下

XML code

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- 
    Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping package="org.yh.vo">
    <class name="org.yh.vo.Count" table="count" catalog="finances">
        <id name="countid" type="java.lang.String">
            <column name="countid" length="25" />
            <generator class="assigned"></generator>
        </id>
        <property name="type" type="java.lang.String">
            <column name="type" length="2" />
        </property>
        <property name="startMoney" type="java.lang.String">
            <column name="startmoney" length="15" />
        </property>
        <property name="remainMoney" type="java.lang.String">
            <column name="remainmoney" length="15" />
        </property>
        <property name="payMoney" type="java.lang.String">
            <column name="paymoney" length="15" />
        </property>
        <set name="moneys" inverse="true" cascade="all">
            <key column = "countid"></key>
            <one-to-many class = "Money"/>
        </set>
    </class>
</hibernate-mapping>

大侠指点下啊，多谢

------解决方案--------------------------------------------------------

探讨

出错的就是红色的那行

------解决方案--------------------------------------------------------
大概是配置的问题，实体类的字段类型和表字段类型对不上。
------解决方案--------------------------------------------------------
String sql = sb.toString();
在这句后加一句
System.out.println("sql: " + sql);
调试，这样可以慢慢自己找答案
------解决方案--------------------------------------------------------
你先不要把List new 出来
 先让List countList = null;
然后 让 countList = query.list();
你试试这样行不行...