SSMP整合案例第二步 数据层dao开发及实现特殊查询

server:
  port: 80
 
#下面这些内容是为了让MyBatis映射
#指定Mybatis的Mapper文件
 
# 专门用来配置的对象datasource
spring:
  datasource:
    druid:
      driver-class-name: com.mysql.jdbc.Driver
      url: jdbc:mysql://localhost:3306/mybatis?serverTimezone=UTC
      username: root
      password: 123456
 
# 配置mybatis-plus
mybatis-plus:
  global-config:
    db—config:
      table-prefix: tbl_

package com.bigdata1421.ssmp.dao;
 
import com.bigdata1421.ssmp.domain.User;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
 
// Mybatis的数据层注解
@Mapper
public interface UserDao {
 
    @Select("select * from tbl_user where id= #{id}")
    User getById(Integer id);
 
}

package com.bigdata1421.ssmp.dao;
 
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.bigdata1421.ssmp.domain.User;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
 
// Mybatis的数据层注解
@Mapper
public interface UserDao extends BaseMapper<User>{
    //Mybatis-plus
    //mp快速开发方案
 
//    @Select("select * from tbl_user where id= #{id}")
//    User getById(Integer id);
 
}

package com.bigdata1421.ssmp.dao;
 
import com.bigdata1421.ssmp.domain.User;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
 
@SpringBootTest
public class UserDaoTestCase {
 
    @Autowired
    private UserDao userDao;
 
    //根据ID查询
    @Test
    void testGetById(){
        System.out.println(userDao.selectById(1));
    }
 
    //增
    @Test
    void testSave(){
        User user=new User();
        user.setId(10);
        user.setName("李懿航");
        user.setAge(20);
        user.setGender(1);
        userDao.insert(user);
    }
 
    //改
    @Test
    void testUpdate(){
        User user=new User();
        user.setId(10);
        user.setName("李懿航");
        user.setAge(20);
        user.setGender(1);
        userDao.updateById(user);
    }
 
    //删
    @Test
    void testDelete(){
        userDao.deleteById(10);
    }
 
    //查询所有数据
    @Test
    void testGetAll(){
        System.out.println( userDao.selectList(null););
    }
 
    //分页查询
    @Test
    void testGetPage(){
    }
 
    //按条件查询
    @Test
    void testGetBy(){
    }
 
}

# 配置mybatis-plus
mybatis-plus:
  global-config:
    db—config:
      table-prefix: tbl_
      id-type: auto
 
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

package com.bigdata1421.ssmp.config;
 
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
 
//拦截器
//一个配置类注解 表示能被spring识别到
@Configuration
public class MPconfig {
    //第三方bean创建注解 创建一个bean容器
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor(){
        MybatisPlusInterceptor interceptor=new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor());
        return interceptor;
    }
}

//分页查询
@Test
void testGetPage(){
    IPage page=new Page(1,3);
    //这是那一页的数据 每一页显示多少数据
    userDao.selectPage(page,null);
}

//按条件查询
@Test
void testGetBy(){
    //容器
    QueryWrapper<User> qw=new QueryWrapper<>();
    //条件
    qw.like("name","高");
    //查询
    userDao.selectList(qw);
}

void testGetBy2(){
    // select * from tbl_ where name like %高%
    //容器
    QueryWrapper<User> qw2=new QueryWrapper<User>();
    //条件
    qw2.like(User::getName,"高");
    //查询
    userDao.selectList(qw2);
}