5.18总结

package com.mf.jdbc.exmaple;

import com.alibaba.druid.pool.DruidDataSourceFactory;
import com.mf.jdbc.Brand;
import org.junit.Test;

import javax.sql.DataSource;
import java.io.FileInputStream;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

/**

• 品牌数据的增删改查
  */

public class BrandTest {

/**
* 查询所有
* 1.SQL：select * from tb_brand
* 2.参数：不需要
* 3.结果：返回List
*/

@Test
public void testSelectALL() throws Exception{
//1.获取Connection
Properties prop = new Properties();
prop.load(new FileInputStream("./src/druid.properties"));
//4.获取连接池对象
DataSource dataSource = DruidDataSourceFactory.createDataSource(prop);

//5.获取数据库连接
Connection conn = dataSource.getConnection();

//定义sql
String sql = "select * from tb_brand;";

//获取pstmt对象
PreparedStatement pstmt = conn.prepareStatement(sql);

//设置参数

//执行sql
ResultSet rs = pstmt.executeQuery();

//处理结果List 封装Brand对象，装在List集合
Brand brand = null;
List brands = new ArrayList<>();
while (rs.next()){
//获取数据
int id = rs.getInt("id");
String brandName = rs.getString("brand_name");
String companyName = rs.getString("company_name");
int ordered = rs.getInt("ordered");
int status = rs.getInt("status");
String description = rs.getString("description");
//封装
brand = new Brand();
brand.setId(id);
brand.setBrandName(brandName);
brand.setCompanyName(companyName);
brand.setOrdered(ordered);
brand.setDescription(description);
brand.setStatus(status);
//装载到集合中去
brands.add(brand);
}
System.out.println(brands);
//释放资源
rs.close();
conn.close();
pstmt.close();

}
}