用eclipse连接mysql数据时,驱动连接不上,提示错误是: No suitable driver found for jdbc: mysql: //localhost: 3306/openlab?user=openlab&password=open123 这个跟你的URL一样? url = "jdbc:mysql://127.0.0.1:3306/myfirst_jdbc"不一样 -_-!
package cn.dao;import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException;/** * * 数据库操作 * * @author 莫小哆_ly 2011-12-31 */ public class DBConn {
是这样加了吧:Class.forName("org.gjt.mm.mysql.Driver");还是不行
是这样加了吧:Class.forName("org.gjt.mm.mysql.Driver");还是不行
No suitable driver found for jdbc: mysql: //localhost: 3306/openlab?user=openlab&password=open123 这个跟你的URL一样?
url = "jdbc:mysql://127.0.0.1:3306/myfirst_jdbc"不一样 -_-!
import java.sql.DriverManager;
import java.sql.SQLException;/**
*
* 数据库操作
*
* @author 莫小哆_ly 2011-12-31
*/
public class DBConn {
private Connection conn;
/**
* 连接数据库
* @return
*/
public Connection getConn(){
String url = "jdbc:mysql://localhost:3306/mydemo"; // 数据库地址[jdbc:mysql://<IP>:<db-port>/<db-name>]
String user = "root"; // 数据库用户名
String pwd = ""; // 数据库密码
try {
Class.forName("com.mysql.jdbc.Driver"); // 加载驱动
conn = DriverManager.getConnection(url, user, pwd);// 注册驱动程序
if (!conn.isClosed()) {
System.out.println("连接成功");
}
if (conn == null) {
System.out.println("连接数据库失败,从检查后重新启动!");
} } catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}
/**
* 关闭数据库连接
*/
public void closeConn(){
if(conn!=null) {
try{
conn.close();
}catch(Exception e){
e.printStackTrace();
}
}
}
}
package cn.impl;import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import java.text.SimpleDateFormat;
import java.util.Date;import cn.dao.DBConn;/**
*
* 本页代码包含 【insert】功能
*
* @author 莫小哆_ly 2011-12-31
*/
public class InsertConOpera {
/**
* 用户注册功能
* @param userName
* @param passWord
*/
public int save(String userName, String passWord) {
int count = 0;
try {
DBConn db = new DBConn();
Connection conn = db.getConn();
// 执行静态SQL语句
Statement stmt = conn.createStatement();
//生成注册时间
Date now = new Date();
SimpleDateFormat format = new SimpleDateFormat("yyyyMMddHHmmss");
String registeredTime = format.format(now); String sql0 = "INSERT INTO user(userName,passWord,registeredTime) " + " VALUES (" + "'"
+ userName + "','" + passWord + "','" + registeredTime + "')";
count = stmt.executeUpdate(sql0);
if (stmt != null) { // 关闭声明
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (conn != null) { // 关闭连接对象
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
db.closeConn();
} catch (SQLException e) {
e.printStackTrace();
}
return count;
}
}我习惯这么用
今天刚开始学jdbc,不会啊
三:Classpath中没有加入合适的mysql_jdbc驱动(驱动要和你的数据库版本一致) 四:驱动jar包放的位置不对我估计是你的url写错拉、你仔细看看。
package com.wxy.jdbc.day01;import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.sql.Connection;import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;public class MYJDBCDemo {
public static final String DBDRIVER = "com.mysql.jdbc.Driver";
//一般都是com.mysql.jdbc.Driver
public static final String URL = "jdbc:mysql://127.0.0.1:3306/myfirst_jdbc";
public static final String DBUSER = "root";
public static final String DBPASSWORD = "root";
public static void getParam(String filename){
Properties props = new Properties();
File file = new File(filename);
try {
FileInputStream fis = new FileInputStream(file);
props.load(fis);
url = props.getProperty("url");
dbUser = props.getProperty("dbUser");
dbPassword = props.getProperty("dbPassword");
} catch (FileNotFoundException e) {
e.printStackTrace();
}
catch (IOException e) {
e.printStackTrace();
}
}
public static void getEmpData(){
Connection conn = null;
Statement stmt = null;
//建议你看看PreparedStatement 它是statement的子类,能实现预处理
ResultSet rs = null;
String sql = "select * from emp";
try {
Class.forName(DBDRIVER);
//加载驱动的jar包
conn = DriverManager.getConnection(URL, DBUSER, DBPASSWORD);
stmt = conn.createStatement();
rs = stmt.executeQuery(sql);
while(rs.next()){
int id = rs.getInt("id");
String name = rs.getString("name");
int age = rs.getInt("age");
System.out.println(id+","+name+","+age);
}
rs.close();
stmt.close();
conn.close();
}
catch (SQLException e) {
e.printStackTrace();
}
}
public static void main(String[] args){
getParam("src/db_mysql.properties");
getEmpData();
}
}最后检查下你的驱动Jar包是否放在了正确的位置。
Class.forName("com.mysql.jdbc.Driver");
}
catch(ClassNotFoundException e) {}
//定义所要用到的三个数据库应用对象
Connection con=null; //连接对象
Statement sql=null; //Statement对象(SQL语句)
ResultSet rs=null; //结果集对象
//进行数据源的连接
try{
con=DriverManager.getConnection ("jdbc:mysql://localhost/scutcs","","");//连接数据库的url 用户名和密码
sql=con.createStatement();
String to="Select * From user1 Where username='"+username+"'";
rs=sql.executeQuery(to); //
pp.load(fis);