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);
            }
        }
    }

}

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mybatis学习使用2简单增删改查