Mybatis查询多条记录并返回List集合

实体对象如下:

private String vend_id;
private String vend_name;
private String vend_address;
private String vend_city;
private String vend_state;
private String vend_zip;
private String vend_country;
private String id;
private String name;

//getter与setter方法...

XML映射文件如下:

<select id="findVendorAll"  resultType="vendors">
    select * from Vendors
</select>

接口文件方法如下: 

//查询所有记录
List<Vendors> findVendorAll();

测试文件如下: 

try {
    String resource = "mybatis-config.xml";
    InputStream resourceAsStream = Resources.getResourceAsStream(resource);
    SqlSessionFactory build = new SqlSessionFactoryBuilder().build(resourceAsStream,"development2");
    //获取SQLSession
    SqlSession openSession = build.openSession();
    VendorMapper mapper = openSession.getMapper(VendorMapper.class);
    List<Vendors> findVendorAll = mapper.findVendorAll();

    System.out.println(findVendorAll);

} catch (IOException e) {
    System.out.println("加载配置文件失败");
    e.printStackTrace();
}

 

笔记:
XML中只需resultType属性值为实体对象别名或全路径名。
mybatis会通过接口文件的返回值类型来判断返回的是集合还是对象。如果是对象，则按常规查询并返回；如果是List集合，mybatis则会将查询到的多条记录设置进集合中并返回。