JDBC

案例 查询account账户表数据,封装为Account 存储到ArrayList

package JDBC.DEMO;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

public class JdbcTest {
    public static void main(String[] args) throws Exception {
        // 注册驱动
        Class.forName("com.mysql.jdbc.Driver");
        // 2.获取链接
        String url = "jdbc:mysql:///db1?useSSL=false";
        String username = "root";
        String password = "1234";
        Connection connection = DriverManager.getConnection(url, username, password);

        //3.定义sql
        String sql = "select * from account";

        //4.获取statement对象
        Statement statement = connection.createStatement();

        //5.执行sql
        ResultSet resultSet = statement.executeQuery(sql);
        List<Account> accounts = new ArrayList<>();
        //6.处理结果 遍历res中所有数据
        // 6.1 光标向下移动一行,并且判断当前行是否有数据
        while (resultSet.next()){
            // 获取数据
            int id = resultSet.getInt(1);
            String name = resultSet.getString(2);
            double money = resultSet.getDouble(3);

            Account account = new Account(id ,name ,money);
            accounts.add(account);

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

package JDBC.DEMO;

public class Account {
    private int id;
    private String name;
    private double money;

    public Account() {
    }

    public Account(int id, String name, double money) {
        this.id = id;
        this.name = name;
        this.money = money;
    }

    public int getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getMoney() {
        return money;
    }

    public void setMoney(double money) {
        this.money = money;
    }

    @Override
    public String toString() {
        return "Account{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", money=" + money +
                '}';
    }
}