MyBatis 开发流程

简介

MyBatis 是一款优秀的持久层框架，它支持自定义 SQL、存储过程以及高级映射。MyBatis 免除了几乎所有的 JDBC 代码以及设置参数和获取结果集的工作。MyBatis 可以通过简单的 XML 或注解来配置和映射原始类型、接口和 Java POJO（Plain Old Java Objects，普通老式 Java 对象）为数据库中的记录。

MyBatis官网：https://github.com/mybatis/mybatis-3

MyBatis开发流程

1.添加jar包

<dependencies>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.4.6</version>
    </dependency>

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.15</version>
    </dependency>

    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
        <scope>test</scope>
    </dependency>

    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.17</version>
    </dependency>
</dependencies>

2. 编写核心配置文件

<environments default="development">
    <environment id="development">
        <transactionManager type="JDBC"/>
        <dataSource type="POOLED">
            <property name="driver" value="${jdbc.dirver}"/>
            <property name="url" value="${jdbc.url}"/>
            <property name="username" value="${jdbc.username}"/>
            <property name="password" value="${jdbc.password}"/>
        </dataSource>
    </environment>
</environments>

3. 新建实体类

public class Dept {

   private Integer id;
   private String dname;
   private String loc;

 

4. 新建mapper接口及映射文件

public interface DeptMapper {

    public List<Dept> getDept();

    public int saveDept(Dept dept);

    public int updDept(@Param("n") String n , @Param("o") String o);

}

<?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.**.mapper.DeptMapper">

    <select id="getDept" resultType="dept">
        select * from dept
    </select>

    <insert id="saveDept" >
        insert into dept(dname,loc) VALUES (#{dname},#{loc})
    </insert>

    <update id="updDept">
        update dept set dname = #{n} where dname = #{o}
    </update>

</mapper>

5. 测试

private SqlSession session;

@Before
public void start(){
    try {
        //读取文件流 mybatis 核心配置
        InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");
        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream);
        session = factory.openSession();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

@Test
public void getDept(){
    DeptMapper mapper = session.getMapper(DeptMapper.class);
    List<Dept> list = mapper.getDept();
    System.out.println(list);
}

@Test
public void saveDept(){
    try {
        DeptMapper mapper = session.getMapper(DeptMapper.class);
        Dept dept = new Dept();
        dept.setDname("市场部");
        dept.setLoc("济南");
        int num = mapper.saveDept(dept);
        session.commit();
        System.out.println("济南");
    }catch (Exception e){
        e.printStackTrace();
    }

}




@Test
public void updDept(){
    DeptMapper dept = session.getMapper(DeptMapper.class);
    int num = dept.updDept("销售部","市场部");
    System.out.println(num);
}



@After
public void colse(){
    if(session != null){
        session.close();
    }
}