JDBC查询实战-优快云博客

本文介绍了一个使用JDBC进行数据库查询的具体实例，展示了如何通过Java代码连接MySQL数据库，并将查询结果映射到自定义的User对象中，最后打印出查询结果。

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JdbcDemo4.java文件：

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

//ResultSet详解
public class JdbcDemo4 {

    public static void main(String[] args) throws Exception {
        Class.forName("com.mysql.jdbc.Driver");
        Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/day15", "root", "");
        Statement stmt = conn.createStatement();
        ResultSet rs = stmt.executeQuery("select id,name,password,email,birthday from users");

//      5、如果是查询语句，需要遍历结果集
        List<User> users = new ArrayList<User>();
        while(rs.next()){
            User user = new User();
            user.setId(rs.getInt("id"));
            user.setName(rs.getString("name"));
            user.setPassword(rs.getString("password"));
            user.setEmail(rs.getString("email"));
            user.setBirthday(rs.getDate("birthday"));

            users.add(user);

        }
        rs.close();
        stmt.close();
        conn.close();

        for(User u:users)
            System.out.println(u);
    }

}

User.java文件：

import java.util.Date;


public class User {

    private int id;
    private String name;
    private String password;
    private String email;
    private Date birthday;
    public User() {
        super();
        // TODO Auto-generated constructor stub
    }
    public User(int id, String name, String password, String email,
            Date birthday) {
        super();
        this.id = id;
        this.name = name;
        this.password = password;
        this.email = email;
        this.birthday = birthday;
    }
    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 String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public Date getBirthday() {
        return birthday;
    }
    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

    @Override
    public String toString() {
        return "User [id=" + id + ", name=" + name + ", password=" + password
                + ", email=" + email + ", birthday=" + birthday + "]";
    }

}

运行结果：
User [id=1, name=zs, password=123456, email=zs@sina.com, birthday=1980-12-04]
User [id=2, name=lisi, password=123456, email=lisi@sina.com, birthday=1981-12-04]
User [id=3, name=wangwu, password=123456, email=wangwu@sina.com, birthday=1979-12-04]