mybatis学习使用2简单增删改查

mybatis的增删改查代码如下demo:

user.java

package com.rookie.bigdata.domain;

import lombok.data;

import java.io.serializable;

/**
 * @author
 * @date 2018/10/21
 */
//data注解可以省略get和set方法
@data
public class user implements serializable{
    // 用户标识
    private integer id;
    // 用户姓名
    private string name;
    // 用户性别
    private string sex;
    // 用户年龄
    private integer age;
    // 无参数构造器
    public user() {
        super();
    }
    // 有参数构造器
    public user( string name, string sex, integer age) {
        super();
        this.name = name;
        this.sex = sex;
        this.age = age;
    }
}

view code

 

usermapper.java

package com.rookie.bigdata.mapper;

import com.rookie.bigdata.domain.user;

/**
 * @author
 * @date 2018/10/21
 */
public interface usermapper {

    void save(user user);

    void saveuser(user user);

    user selectuser(integer id);

    void updateuser(user user);

    void deleteuser(integer id);

}

 

usermapper.xml

<?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.rookie.bigdata.mapper.usermapper">


  <insert id="save" parametertype="com.rookie.bigdata.domain.user" usegeneratedkeys="true">
      insert into bs_user(name,sex,age)
      values(#{name},#{sex},#{age})
  </insert>

    <!--
    parametertype="user"表示该插入语句需要一个user对象作为参数
    usegeneratedkeys="true"表示使用自动增长的主键,即使用jdbc的getgeeratedkeys方法获取由数据库生疮内部生成的主键，默认为false
    keyproperty唯一标记的一个属性，mybatis会通过getgerneratedkeys的返回值设置它的键值-->
    <insert id="saveuser" parametertype="com.rookie.bigdata.domain.user"
            usegeneratedkeys="true" keyproperty="id">
        insert into bs_user(name,sex,age)
        values(#{name},#{sex},#{age})
    </insert>

    <!-- select操作
    parametertype="int"表示该查询语句需要一个int类型的参数
    resulttype="com.rookie.bigdata.domain.user"表示返回的是一个user对象 -->
    <select id="selectuser" parametertype="int" resulttype="com.rookie.bigdata.domain.user">
        select * from bs_user where id = #{id}
    </select>

    <!-- update操作
    parametertype="com.rookie.bigdata.domain.user"表示该更新语句需要一个user对象作为参数-->
    <update id="updateuser" parametertype="com.rookie.bigdata.domain.user">
        update bs_user
        set name = #{name},sex = #{sex},age = #{age}
        where id = #{id}
    </update>

    <!-- delete操作 parametertype="int"表示该查询语句需要一个int类型的参数-->
    <delete id="deleteuser" parametertype="int">
        delete from bs_user where id = #{id}
    </delete>

</mapper>

 

mybatis-config.xml

<?xml version="1.0" encoding="utf-8" ?>
<!doctype configuration
  public "-//mybatis.org//dtd config 3.0//en"
  "http://mybatis.org/dtd/mybatis-3-config.dtd">
  <!--  xml 配置文件包含对 mybatis 系统的核心设置 -->
<configuration>

<!--    <typealiases>
        <typealias  alias="user" type="com.rookie.bigdata.domain.user"/>
    </typealiases>-->
    <environments default="mysql">
    <!-- 环境配置，即连接的数据库。 -->
    <environment id="mysql">
    <!--  指定事务管理类型，type="jdbc"指直接简单使用了jdbc的提交和回滚设置 -->
      <transactionmanager type="jdbc"/>
      <!--  datasource指数据源配置，pooled是jdbc连接对象的数据源连接池的实现。 -->
      <datasource type="pooled">
        <property name="driver" value="com.mysql.jdbc.driver"/>
        <property name="url" value="jdbc:mysql://127.0.0.1:3306/mybatis"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
      </datasource>
    </environment>
  </environments>
  <!-- mappers告诉了mybatis去哪里找持久化类的映射文件 -->
  <mappers>
      <mapper resource="mapper/usermapper.xml"/>
  </mappers>
</configuration>

 

测试代码usermappertest.java

package com.rookie.bigdata.mapper;

import com.rookie.bigdata.domain.user;
import org.apache.ibatis.annotations.mapper;
import org.apache.ibatis.io.resources;
import org.apache.ibatis.session.sqlsession;
import org.apache.ibatis.session.sqlsessionfactory;
import org.apache.ibatis.session.sqlsessionfactorybuilder;
import org.junit.before;
import org.junit.test;

import java.io.ioexception;
import java.io.inputstream;


/**
 * @author
 * @date 2018/10/21
 */
public class usermappertest {

    public  sqlsession session;

    @before
    public void before() throws ioexception {
        // 读取mybatis-config.xml文件
        inputstream inputstream = resources.getresourceasstream("mybatis-config.xml");
        // 初始化mybatis，创建sqlsessionfactory类的实例
        sqlsessionfactory sqlsessionfactory = new sqlsessionfactorybuilder()
                .build(inputstream);
        // 创建session实例
         session = sqlsessionfactory.opensession();
    }

    @test
    public void saveuser() throws exception {



        usermapper mapper = session.getmapper(usermapper.class);

        mapper.saveuser(new user("zhangsan","男",23));

        session.commit();
        // 关闭session
        session.close();
    }

    @test
    public void selectuser() throws exception {
        usermapper mapper = session.getmapper(usermapper.class);
        user user = mapper.selectuser(5);

        // 提交事务
        session.commit();
        // 关闭session
        session.close();
        system.out.println(user);
    }

    @test
    public void updateuser() throws exception {
        usermapper mapper = session.getmapper(usermapper.class);
        user user = mapper.selectuser(5);
        user.setage(21);

        mapper.updateuser(user);
        // 提交事务
        session.commit();
        // 关闭session
        session.close();
        system.out.println(user);

    }

    @test
    public void deleteuser() throws exception {

        usermapper mapper = session.getmapper(usermapper.class);
        mapper.deleteuser(5);
        session.commit();
        // 关闭session
        session.close();



    }

}

 

关联查询的代码如下：

staff.java

package com.rookie.bigdata.domain;

import lombok.data;

/**
 * @author 
 * @date 2018/10/21
 */
@data
public class staff {
    private integer id;
    private string name;
    private string sex;
    private integer age;

    private department department;
}

view code

 

department.java

package com.rookie.bigdata.domain;

import lombok.data;

import java.util.list;

/**
 * @author liuxili
 * @date 2018/10/21
 */
@data
public class department {
    private integer id;
    private string code;

    private list<staff> staffs;
}

view code

 

companymapper.java

package com.rookie.bigdata.mapper;

import com.rookie.bigdata.domain.department;
import com.rookie.bigdata.domain.staff;

import java.util.list;

/**
 * @author
 * @date 2018/10/21
 */
public interface companymapper {


    list<staff> selectstaff();

    list<department> selectdepartment();
}

 

companymapper.java

<?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.rookie.bigdata.mapper.companymapper">

<!--职工映射对象-->
    <resultmap id="staffresultmap" type="com.rookie.bigdata.domain.staff">
        <id property="id" column="id"/>
        <result property="name" column="name"/>
        <result property="sex" column="sex"/>
        <result property="age" column="age"/>
        <!--进行关联映射-->
        <association property="department" column="depart_id" javatype="com.rookie.bigdata.domain.department"
                     select="selectid"/>
    </resultmap>
    <!--根据id查询相关部门-->
    <select id="selectid" resulttype="com.rookie.bigdata.domain.department">
        select * from bs_department where id=#{id};
    </select>

    <select id="selectstaff" resultmap="staffresultmap">
        select * from bs_staff;
    </select>

    <resultmap id="departresultmap" type="com.rookie.bigdata.domain.department">
        <id property="id" column="id"/>
        <result property="code" column="code"/>
　　　　<!--javatype:属性对应的类型
　　　　　　oftype：表示集合当中的类型-->
        <collection property="staffs" javatype="arraylist" column="id" oftype="com.rookie.bigdata.domain.staff"
                    select="selectstaffbyid"/>
    </resultmap>
    <select id="selectstaffbyid" resulttype="com.rookie.bigdata.domain.staff">
        select * from  bs_staff where depart_id=#{id}
    </select>
    <select id="selectdepartment" resultmap="departresultmap">
        select * from bs_department;
    </select>
</mapper>

 

测试代码companymappertest.java

package com.rookie.bigdata.mapper;

import com.rookie.bigdata.domain.department;
import com.rookie.bigdata.domain.staff;
import org.apache.ibatis.io.resources;
import org.apache.ibatis.session.sqlsession;
import org.apache.ibatis.session.sqlsessionfactory;
import org.apache.ibatis.session.sqlsessionfactorybuilder;
import org.junit.before;
import org.junit.test;

import java.io.ioexception;
import java.io.inputstream;
import java.util.list;

import static org.junit.assert.*;

/**
 * @author
 * @date 2018/10/21
 */
public class companymappertest {
    public sqlsession session;

    @before
    public void before() throws ioexception {
        // 读取mybatis-config.xml文件
        inputstream inputstream = resources.getresourceasstream("mybatis-config.xml");
        // 初始化mybatis，创建sqlsessionfactory类的实例
        sqlsessionfactory sqlsessionfactory = new sqlsessionfactorybuilder()
                .build(inputstream);
        // 创建session实例
        session = sqlsessionfactory.opensession();
    }


    @test
    public void selectstaff() throws exception {

        companymapper mapper = session.getmapper(companymapper.class);
        list<staff> staff = mapper.selectstaff();
        for (staff staff1 : staff) {
            system.out.println(staff1);
        }

        session.commit();
        session.close();
    }

    @test
    public void selectdepartment(){
        companymapper mapper = session.getmapper(companymapper.class);
        list<department> departments = mapper.selectdepartment();
        for (department department : departments) {
            list<staff> staffs = department.getstaffs();
            for (staff staff : staffs) {
                system.out.println(department);
                system.out.println(staff);
            }
        }
    }

}