大数据------JavaWeb------MyBatis（完整知识点汇总）
package at.guigu.test;
import at.guigu.mapper.BrandMapper;
import at.guigu.pojo.Brand;
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.Test;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class MyBatisTest {
private static BrandMapper getBrandMapper() throws IOException {
//1 加载核心配置文件，获取`SqlSessionFactory`对象
//1.1 配置mybatis-config.xml文件路径，由于该文件直接在resources目录下，所以直接写文件名即可
String resource = "mybatis-config.xml";
//1.2 利用Resources类中的静态方法将配置文件加载到内存
InputStream inputStream = Resources.getResourceAsStream(resource);
//1.3 获取SqlSessionFactory对象
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2 获取SqlSession对象，执行SQL语句
//2.1 获取SqlSession对象
SqlSession sqlSession = sqlSessionFactory.openSession();
//2.2 获取Mapper接口UserMapper的代理对象
BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
return brandMapper;
}
//多条件查询方式一：散装参数接收
@Test
public void testSelectByCondition() throws IOException {
//接收前端传回的多条件参数
int status = 1;
String companyName = "华为";
String brandName = "华为";
//处理参数
companyName = "%" + companyName + "%";
brandName = "%" + brandName + "%";
//获取Mapper接口对象
BrandMapper brandMapper = getBrandMapper();
//2.3 执行sql语句
List<Brand> brands = brandMapper.selectByCondition(status, companyName, brandName);
System.out.println(brands);
}
//多条件查询方式二：对象参数接收
@Test
public void testSelectByConditionTwo() throws IOException {
//接收前端传回的多条件参数
int status = 1;
String companyName = "华为";
String brandName = "华为";
//处理参数
companyName = "%" + companyName + "%";
brandName = "%" + brandName + "%";
//将多条件参数封装到对象中
Brand brand = new Brand();
brand.setStatus(status);
brand.setCompanyName(companyName);
brand.setBrandName(brandName);
//获取Mapper接口对象
BrandMapper brandMapper = getBrandMapper();
//2.3 执行sql语句
List<Brand> brands = brandMapper.selectByCondition(brand);
System.out.println(brands);
}
//多条件查询方式三：Map集合参数接收
@Test
public void testSelectByConditionThree() throws IOException {
//接收前端传回的多条件参数
int status = 1;
String companyName = "华为";
String brandName = "华为";
//处理参数
companyName = "%" + companyName + "%";
brandName = "%" + brandName + "%";
//将多条件参数封装到对象中
Map map = new HashMap();
map.put("status", status);
map.put("companyName", companyName);
map.put("brandName", brandName);
//获取Mapper接口对象
BrandMapper brandMapper = getBrandMapper();
//2.3 执行sql语句
List<Brand> brands = brandMapper.selectByCondition(map);
System.out.println(brands);
}
}