3.21每日总结

package com;

import java.sql.*;

public class DB {
    public Connection conn = null;
    public Statement stmt = null;
    public ResultSet rs = null;
    String url = "jdbc:mysql://localhost:3306/subway?useSSL=false&serverTimezone=UTC";
    String username = "root";
    String password = "1506583922";
    public DB(){
        try{
            Class.forName("com.mysql.cj.jdbc.Driver");
            conn = DriverManager.getConnection(url,username,password);
            stmt = conn.createStatement();
        }catch(SQLException se){
            // 处理 JDBC 错误
            se.printStackTrace();
        }catch(Exception e){
            // 处理 Class.forName 错误
            e.printStackTrace();
        }
    }
    public void close(){
        try {
            if (rs!=null){
                rs.close();
            }
            if (stmt!=null){
                stmt.close();
            }
            if (conn!=null){
                conn.close();
            }
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }


}

package com;

import dao.Sub;

import java.sql.PreparedStatement;
import java.sql.SQLException;

public class DBC {

    public void CreateTable(){


        Sub sub =new Sub();
        PreparedStatement preparedStatement=null;
        try {
            DB db = new DB();
            String sql ="CREATE TABLE IF NOT EXISTS `linktable`(" +
                        "`Id` INT UNSIGNED AUTO_INCREMENT ," +
                        "`Alink` VARCHAR(255) NOT NULL ," +
                        "`Blink` VARCHAR(255) NOT NULL ," +
                        "`Clink` VARCHAR(255) NOT NULL ," +
                        "`Tname` VARCHAR(255) NOT NULL ," +
                        "PRIMARY KEY(`Id`)" +
                        ")ENGINE=INNODB DEFAULT CHARSET=utf8";
            preparedStatement=db.conn.prepareStatement(sql);
            preparedStatement.executeUpdate();
            db.close();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally{
        }
        try {
            DB db = new DB();
            String b = "linktable";
            String sqc = "SELECT * FROM " + b ;
            preparedStatement=db.conn.prepareStatement(sqc);
            preparedStatement.executeQuery();
            while (db.rs.next()){
                String equ = String.valueOf(db.rs.next());

                for (int i = 0; i < 1; i++) {

                }
            }
            db.close();
        }catch (SQLException e){
            e.printStackTrace();
        }finally {

        }

    }
    public void InsertFull(String table_name,String Id,String Alink,String Blink,String Clink,String Tname){
        DB db = new DB();
        PreparedStatement preparedStatement=null;
        try {
            String sql = "INSERT INTO "+ table_name + " (Id,Alink,Blink,Clink,Tname) values (?,?,?,?,?)";
            preparedStatement=db.conn.prepareStatement(sql);
            preparedStatement.setString(1,Id);
            preparedStatement.setString(2,Alink);
            preparedStatement.setString(3,Blink);
            preparedStatement.setString(4,Clink);
            preparedStatement.setString(5,Tname);
            preparedStatement.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally{
        }

    }


}