mysql_jdbc

package com.lovo.day18_jdbc1;


import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;


public class TestMain {


/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub

//获取连接--通用代码
Connection con = null;
try {
Class.forName("com.mysql.jdbc.Driver");         //载入驱动类
con = DriverManager.getConnection("jdbc:mysql://localhost:3306/数据库名",         
"账号", "password");
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

//新增记录
//构造sql语句
String sql = "insert into t_user(f_username,f_password,f_account) values(?,?,?

)";
System.out.println(sql);
try {
//获取预编译语句对象
PreparedStatement ps = con.prepareStatement(sql);
ps.setString(1, "zhang6");
ps.setString(2, "123456");
ps.setDouble(3, 16000);
//运行sql
int row = ps.executeUpdate();
System.out.println(row);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
if(con != null){
try {
con.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

//查询语句---查询单条记录
// UserInfo theUser = null;
// String inputName = JOptionPane.showInputDialog("请输入username:");
// String inputPwd = JOptionPane.showInputDialog("请输入password:");
// String sql = "select * from t_user where f_username = '"
// + inputName + "' and f_password = '" + inputPwd + "'";
// System.out.println(sql);
// try {
// Statement stat = con.createStatement();
// ResultSet rs = stat.executeQuery(sql);
// while(rs.next()){
// theUser = new UserInfo();
// theUser.setId(rs.getInt(1));
// theUser.setUsername(rs.getString(2));
// theUser.setPassword(rs.getString(3));
// theUser.setAccount(rs.getDouble(4));
// }
//
// } catch (SQLException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// } finally{
// if(con != null){
// try {
// con.close();
// } catch (SQLException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// }
// }
// }
//  //做一个推断来看成功是否
// if(theUser == null){
// JOptionPane.showMessageDialog(null, "登录失败!");
// }else{
// JOptionPane.showMessageDialog(null, "登录成功!

您的剩余金额是:" + theUser.getAccount() + "元!

");
// }

//查询多条记录
// ArrayList<UserInfo> allUsers = new ArrayList<UserInfo>();            //用一个集合来装
// String sql = "select * from t_user where f_account > 12000";
// try {
// Statement stat = con.createStatement();
// ResultSet rs = stat.executeQuery(sql);
// while(rs.next()){
// UserInfo theUser = new UserInfo();
// theUser.setId(rs.getInt(1));
// theUser.setUsername(rs.getString(2));
// theUser.setPassword(rs.getString(3));
// theUser.setAccount(rs.getDouble(4));
//
// allUsers.add(theUser);
// }
// } catch (SQLException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// } finally{
// if(con != null){
// try {
// con.close();
// } catch (SQLException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// }
// }
// }


//预编译语句
// UserInfo theUser = null;
// String inputName = JOptionPane.showInputDialog("请输入username:");
// String inputPwd = JOptionPane.showInputDialog("请输入password:");
// String sql = "select * from t_user where f_username = ?

and f_password = ?

";
// System.out.println(sql);
// try {
// PreparedStatement ps = con.prepareStatement(sql);
// ps.setString(1, inputName);
// ps.setString(2, inputPwd);
//
// ResultSet rs = ps.executeQuery();
// while(rs.next()){
// theUser = new UserInfo();
// theUser.setId(rs.getInt(1));
// theUser.setUsername(rs.getString(2));
// theUser.setPassword(rs.getString(3));
// theUser.setAccount(rs.getDouble(4));
// }
//
// } catch (SQLException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// } finally{
// if(con != null){
// try {
// con.close();
// } catch (SQLException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// }
// }
// }
//
// if(theUser == null){
// JOptionPane.showMessageDialog(null, "登录失败!");
// }else{
// JOptionPane.showMessageDialog(null, "登录成功!您的剩余金额是:" + theUser.getAccount() + "元!");
// }


}


}

原文地址:https://www.cnblogs.com/claireyuancy/p/6940830.html