JDBC练习查询所有内容

MySql表代码

-- 删除tb_brand表
drop table if exists tb_brand;
-- 创建tb_brand表
create table tb_brand
(
    -- id 主键
    id           int primary key auto_increment,
    -- 品牌名称
    brand_name   varchar(20),
    -- 企业名称
    company_name varchar(20),
    -- 排序字段
    ordered      int,
    -- 描述信息
    description  varchar(100),
    -- 状态：0：禁用  1：启用
    status       int
);
-- 添加数据
insert into tb_brand (brand_name, company_name, ordered, description, status)
values ('三只松鼠', '三只松鼠股份有限公司', 5, '好吃不上火', 0),
       ('华为', '华为技术有限公司', 100, '华为致力于把数字世界带入每个人、每个家庭、每个组织，构建万物互联的智能世界', 1),
       ('小米', '小米科技有限公司', 50, 'are you ok', 1);


SELECT * FROM tb_brand;

package example;

import org.gjt.mm.mysql.Driver;
import org.junit.Test;
import pojo.Account;

import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class BrandTest {

    @Test
    public void tsetSelectAll() throws Exception {

        //查询所有sql
        //注册链接
        String url = "jdbc:mysql://127.0.0.1:3306/heimalearnmysql?useSSL=false";
        String username = "root";
        String password = "1234";
        Connection connection = DriverManager.getConnection(url, username, password);

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

        //获取statement对象
        Statement statement = connection.createStatement();

        //执行sql
        ResultSet resultSet = statement.executeQuery(sql);

        //集合存储啦
        List<Account> accounts = new ArrayList<>();
        //处理结果

        while (resultSet.next()){
            Integer id = resultSet.getInt(1);
            String brand_name = resultSet.getString(2);
            String company_name=resultSet.getString(3);
            Integer ordered= resultSet.getInt(4);
            String description=resultSet.getString(5);
            Integer status=resultSet.getInt(6);

            Account account = new Account(id , brand_name , company_name,ordered,description,status);
            accounts.add(account);

        }

        for (Account account : accounts) {
            System.out.println(account);
        }

    }
}

Account 类代码

package pojo;

public class Account {
    // id 主键
    private Integer id;
    // 品牌名称
    private String brand_name;
    // 企业名称
    private String company_name;
    // 排序字段
    private Integer ordered;
    // 描述信息
    private String description;
    // 状态：0：禁用  1：启用
    private Integer status;

    public Account(Integer id, String brand_name, String company_name, Integer ordered, String description, Integer status) {
        this.id = id;
        this.brand_name = brand_name;
        this.company_name = company_name;
        this.ordered = ordered;
        this.description = description;
        this.status = status;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getBrand_name() {
        return brand_name;
    }

    public void setBrand_name(String brand_name) {
        this.brand_name = brand_name;
    }


    public String getCompany_name() {
        return company_name;
    }

    public void setCompany_name(String company_name) {
        this.company_name = company_name;
    }

    public Integer getOrdered() {
        return ordered;
    }

    public void setOrdered(Integer ordered) {
        this.ordered = ordered;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public Integer getStatus() {
        return status;
    }

    public void setStatus(Integer status) {
        this.status = status;
    }

    @Override
    public String toString() {
        return "Account{" +
                "id=" + id +
                ", brand_name='" + brand_name + '\'' +
                ", company_name='" + company_name + '\'' +
                ", ordered=" + ordered +
                ", description='" + description + '\'' +
                ", status=" + status +
                '}';
    }
}```