JDBC 简单增删改查

利用sql语句写出简单的增删改查

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


/**
*2018年12月27日
*JDBC_CRUD.java
*/

public class JDBC_CRUD {
    // JDBC 驱动名及数据库 URL
    static final String URL = "jdbc:mysql://localhost:3306/lesson?serverTimezone=Hongkong";
    
    // 数据库的用户名与密码，需要根据自己的设置
    static final String USER = "root";
    static final String PASSWORD = "123456";
    private static boolean initialize = true;
    
    static{
        //利用反射的原理检测驱动类是否存在
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
            initialize = false;
        }
    }
    
    public static void main(String[] args) {
//        查询打印
//        List<member>members = query();
//        members.forEach(s->System.out.println(s));
        String sqlinsert = "insert into memberinfo values(default,'小文',1,26,'五道口',20,'普通用户',155789)";
        String sqldelete = "delete from memberinfo where id = 7";
        change(sqldelete);
        
    }
    
    //查询数据库数据
    public static List<member> query() {
        List<member>members = new ArrayList<>();
        
        try {
            Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
            Statement s = conn.createStatement();
            String sql = "SELECT * FROM memberinfo";
            ResultSet rs = s.executeQuery(sql);
            
            while (rs.next()) {
                int id = rs.getInt("id");
                String name = rs.getString("name");
                int sex = rs.getInt("sex");
                int age = rs.getInt("age");
                String address = rs.getString("Address");
                long point = rs.getLong("point");
                String level = rs.getString("level");
                int postnumber = rs.getInt("postnumber");
                member m = new member();
                m.setId(id);
                m.setName(name);
                m.setSex(sex);
                m.setAge(age);
                m.setAddress(address);
                m.setPoint(point);
                m.setLevel(level);
                m.setPostnumber(postnumber);
                members.add(m);
            }
            s.close();
            conn.close();
            
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return members;
    }
    //修改数据（增、删、改）
    public static void change(String sql) {
        try {
            Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
            Statement s = conn.createStatement();
            s.executeUpdate(sql);
            s.close();
            conn.close();
            System.out.println("执行完成！");
            
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    
}