mybatis映射文件mapper.xml的具体写法

<?xml version="1.0" encoding="utf-8" ?>
<!doctype mapper
public "-//mybatis.org//dtd mapper 3.0//en"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.qbd.mapper.studentmappers">
    <select id="findbyid" parametertype="integer" resultmap="studentresult">
        select *from student where id=#{id}
    </select>
    
    <select id="findbygradeid" parametertype="integer" resultmap="studentresult">
        select *from student where gid=#{gid}
    </select>
    
    <resultmap type="student" id="studentresult">
        <id property="id" column="id"/>
        <result property="name" column="name"/>
        <result property="age" column="age"/>
        <association property="address" column="addid" select="com.qbd.mapper.addressmappers.findbyid">    
        </association>
        <association property="grade" column="gid" select="com.qbd.mapper.grademappers.findbyid">    
        </association>
    </resultmap>
</mapper>

package com.qbd.service;
import org.apache.ibatis.session.sqlsession;
import org.apache.log4j.logger;
 
import com.qbd.mapper.studentmappers;
import com.qbd.model.student;
import com.qbd.util.sqlsessionfactoryutil;
 
public class studentservice {
    private static logger logge=logger.getlogger(studentservice.class);
    public static void main(string[] args) {
        sqlsession sqlsession=sqlsessionfactoryutil.getsqlsession();
        
        studentmappers studentmappers=(studentmappers)sqlsession.getmapper(studentmappers.class);
        student student=new student();
        student.setname("22");
        student.setage(2);
        int s=studentmappers.add(student);
        sqlsession.commit();
        if(s>0){
            logge.info("success");
            system.out.println("success");
        }
        
    }
}

<?xml version="1.0" encoding="utf-8" ?>
<!doctype mapper
public "-//mybatis.org//dtd mapper 3.0//en"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.qbd.ssm.dao.userdao">
    <!-- 定义缓存  一般是一级缓存，如果用同一个sqlsession 那么相同查询直接会从缓存中查找 
    <cache size="1024" flushinterval="60000" eviction="lru" readonly="false"></cache>
    -->
    <!-- 查找所有 -->
    <select id="find" parametertype="map" resultmap="studentresult">
        select * from user
        <where>
            <if test="uname!=null and uname!='' ">
                and uname like #{uname}
            </if>
        </where>
        <if test="start!=null and size!=null">
            limit #{start},#{size}
        </if>
    </select>
    
    <select id="gettotal" parametertype="map" resulttype="long">
        select count(*) from user
        <where>
            <if test="uname!=null and uname!='' ">
                and uname like #{uname}
            </if>
        </where>
    </select>
    <!-- 按照用户名和密码查找 -->
    <select id="getuser" resultmap="studentresult" parametertype="map">
        select *from user where uname=#{uname} and upassword=#{upassword}
    </select>
    <!-- 删除 -->
    <delete id="delete" parametertype="map">
        delete from user where uid=#{uid}
    </delete>
    <!-- 修改 -->
    <update id="update" parametertype="user">
        update user
        <set>
            <if test="uname!=null">
                 uname=#{uname},
            </if>
            <if test="upassword!=null">
                upassword=#{upassword},
            </if>
            <if test="upower!=null">
                upower=#{upower},
            </if>
        </set>
        where uid=#{uid}
    </update>
    <!-- 增加 -->
    <insert id="add" parametertype="user">
        insert into user values(null,#{uname},#{upassword},#{upower})
    </insert>
    <resultmap type="user" id="studentresult">
        <id property="uid" column="uid"/>
        <result property="uname" column="uname"/>
        <result property="upassword" column="upassword"/>
    </resultmap>
</mapper>

package com.qbd.ssm.dao;
 
import java.util.list;
import java.util.map;
 
import org.apache.ibatis.annotations.delete;
 
import com.qbd.ssm.model.user;
 
public interface userdao {
 
    public list<user> getall();
    public user getuser(user user);
    public int delete(user user);
    public int update(user user);
    public int add(user user);
    public list<user> find(map<string,object> map);
    public long gettotal(map<string,object> map);
}

package com.qbd.ssm.service;
import java.util.list;
import java.util.map;
import com.qbd.ssm.model.user; 
public interface userservice {
 
    public list<user> getall();
    public user getuser(user user);
    public int delete(user user);
    public int update(user user);
    public int add(user user);
    public list<user> find(map<string,object> map);
    public long gettotal(map<string,object> map);
}

package com.qbd.ssm.serviceimpl;
import java.util.list;
import java.util.map;
import javax.annotation.resource; 
import org.springframework.beans.factory.annotation.autowired;
import org.springframework.stereotype.service;
import com.qbd.ssm.dao.userdao;
import com.qbd.ssm.model.user;
import com.qbd.ssm.service.userservice;
 
@service("userservice")
public class userserviceimpl implements userservice {
 
    private userdao userdao;
    
    public userdao getuserdao() {
        return userdao;
    }
 
    @resource
    public void setuserdao(userdao userdao) {
        this.userdao = userdao;
    }
 
    public list<user> getall() {
        // todo auto-generated method stub
        return userdao.getall();
    }
 
    public user getuser(user user) {
        // todo auto-generated method stub
        return userdao.getuser(user);
    }
 
    public int delete(user user) {
        // todo auto-generated method stub
        return userdao.delete(user);
    }
 
    public int update(user user) {
        // todo auto-generated method stub
        return userdao.update(user);
    }
 
    public int add(user user) {
        // todo auto-generated method stub
        return userdao.add(user);
    }
 
    public list<user> find(map<string, object> map) {
        // todo auto-generated method stub
        return userdao.find(map);
    }
 
    public long gettotal(map<string, object> map) {
        // todo auto-generated method stub
        return userdao.gettotal(map);
    }
}