//测试查询
@Test
public void testSelect(){
User user = userMapper.selectById(1L);
System.out.println(user);
}
2.批量查询
@Test
public void testSelect(){
//单个数据查询
//User user = userMapper.selectById(1L);
//System.out.println(user);
//测试批量查询
List users = userMapper.selectBatchIds(Arrays.asList(1, 2, 3));
users.forEach(System.out::println);
}
3. 测试条件查询
//测试条件查询 map
@Test
public void testselectmap(){
HashMap map1 = new HashMap<>();
//自定义查询
map1.put("name","左小妹");
List users = userMapper.selectByMap(map1);
users.forEach(System.out::println);
}
//测试条件查询 map
@Test
public void testselectmap(){
HashMap map1 = new HashMap<>();
//自定义查询
map1.put("name","左小妹");
map1.put("age",18);
List users = userMapper.selectByMap(map1);
users.forEach(System.out::println);
}
分页查询
1. 原始的limit分页查询
2.第三方插件（pagehelper）
3.MP中内置了分页插件（1）配置拦截器
//分页插件
@Bean
public PaginationInnerInterceptor paginationInnerInterceptor(){
PaginationInnerInterceptor paginationInnerInterceptor = new PaginationInnerInterceptor();
return paginationInnerInterceptor;
}
（2）直接使用Page对象即可
//测试分页插件
@Test
public void testPage(){
Page page = new Page<>(2,3);//当前页、页面大小
userMapper.selectPage(page,null);
page.getRecords().forEach(System.out::println);
}
