正文
java连接jdbc代码,java连接数据库jdbc
提示：扫一扫查出行【扫一扫了解最新限行尾号】
复制提示
java连接数据库的代码
用这个类吧.好的话,给我加加分.
import java.sql.*;
/**
* @功能: 一个JDBC的本地化API连接类,封装了数据操作方法,只用传一个SQL语句即可
* @作者: 李开欢
* @日期: 2007/
*/
public class ConnectionDemo {
/*
* 这里可以将常量全部放入另一个类中,以方便修改
*/
private static Connection conn;
private static Statement ps;
private static ResultSet rs;
private static final String DRIVER = "com.microsoft.jdbc.sqlserver.SQLServerDriver";
private static final String URL = "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=mydb";
private static final String USER ="sa";
private static final String PASS = "sa";
public ConnectionDemo() {
// TODO Auto-generated constructor stub
ConnectionDemo.getConnection();
}
public static Connection getConnection(){
System.out.println("连接中...");
try {
Class.forName(ConnectionDemo.DRIVER);
conn = DriverManager.getConnection(ConnectionDemo.URL, ConnectionDemo.USER, ConnectionDemo.PASS);
System.out.println("成功连接");
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return conn;
}
public static Statement getStatement(String sql){
System.out.println("执行SQL语句中...");
try {
ps = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE);
if(sql.substring(0, 6).equals("select")){
rs = ps.executeQuery(sql);
System.out.println("执行完查询操作,结果已返回ResultSet集合");
}else if(sql.substring(0, 6).equals("delete")){
ps.executeUpdate(sql);
System.out.println("已执行完毕删除操作");
}else if(sql.substring(0, 6).equals("insert")){
ps.executeUpdate(sql);
System.out.println("已执行完毕增加操作");
}else{
ps.executeUpdate(sql);
System.out.println("已执行完毕更新操作");
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return ps;
}
public static ResultSet getResultSet(){
System.out.println("查询结果为:");
return rs;
}
public static void closeConnection(){
System.out.println("关闭连接中...");
try {
if (rs != null) {
rs.close();
System.out.println("已关闭ResultSet");
}
if (ps != null) {
ps.close();
System.out.println("已关闭Statement");
}
if (conn != null) {
conn.close();
System.out.println("已关闭Connection");
}
} catch (Exception e) {
// TODO: handle exception
}
}
public static void main(String[] args) {
// TODO Auto-generated method stub
ConnectionDemo.getConnection();
String sql = "delete from type where id = 1";
ConnectionDemo.getStatement(sql);
String sql2 = "insert into type values(1,'教学设备')";
ConnectionDemo.getStatement(sql2);
String sql1 = "select * from type";
ConnectionDemo.getStatement(sql1);
ResultSet rs = ConnectionDemo.getResultSet();
System.out.println("编号 "+"类 型");
try {
while(rs.next()){
System.out.print(" "+rs.getInt(1)+" ");
System.out.println(rs.getString(2));
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
ConnectionDemo.closeConnection();
}
}
相关问答
Q1: 利用java代码,编写JDBC连接数据库新增员工信息的步骤. 员工信息表:t_emp(id int？
第一步：新建数据库
连接的是本地localhost，新建一个新的数据库名是jdbctest
然后建表t_emp
不会的话可通过执行下方的sql语句建表
CREATE TABLE `t_emp` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(255) DEFAULT NULL,
`salary` double DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;
第二步：新建java项目
新建完以后添加mysql驱动的jar包，jar包自己下载
在项目上右键鼠标属性，然后
添加jar包，我这里已经加载过了
第三步：编写代码
package com.gf;
import java.sql.DriverManager;
import java.sql.SQLException;
import com.mysql.jdbc.Connection;
import com.mysql.jdbc.Statement;
public class Test {
public static void main(String[] args) throws Exception {
int flag=0;
//1.加载驱动
Class.forName("com.mysql.jdbc.Driver");
//2.获取连接
Connection conn=(Connection) DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/jdbctest?user=rootpassword=123456useUnicode=truecharacterEncoding=UTF-8");
//3.创建statement
Statement sm=(Statement) conn.createStatement();
//4.执行sql语句
flag=sm.executeUpdate("insert into t_emp(name,salary) values('菲菲',34.9)");
if(flag!=0) {
System.out.println("员工信息增加成功");
}else {
System.out.println("添加失败");
}
}
}
注意点：
---------------------------------------------------------------------------------
DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/jdbctest?user=rootpassword=123456useUnicode=truecharacterEncoding=UTF-8");
这里需要修改自己本机的连接信息，不然会出现连接失败
最后的执行结果
Q2: java 实现 jdbc连接oracle 数据库的java代码怎么写
package com.jdbc.test;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
public class JDBCTest {
public static void main(String[] args) throws Exception {
//1.加载驱动
//Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
//Class.forName("com.mysql.jdbc.Driver");
Class.forName("oracle.jdbc.driver.OracleDriver");
//2.创建数据库连接对象
//Connection conn = DriverManager.getConnection("jdbc:sqlserver://localhost:1433;databaseName=db","sa","sqlpass");
//Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/db?useUnicode=truecharacterEncoding=UTF-8","root","123456");
Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:orcl","scott","Oracle123");
//3.创建数据库命令执行对象
Statement stmt = conn.createStatement();
// PreparedStatement ps = conn.prepareStatement("select * from t_user");
//4.执行数据库命令
ResultSet rs = stmt.executeQuery("select * from t_user");
// ResultSet rs = ps.executeQuery();
//5.处理执行结果
while (rs.next()) {
int id = rs.getInt("id");
String username = rs.getString("username");
String password = rs.getString("password");
System.out.println(id + "\t" + username + "\t" + password);
}
//6.释放数据库资源
if (rs != null) {
rs.close();
}
// if (ps != null) {
// ps.close();
// }
if (stmt != null) {
stmt.close();
}
if (conn != null) {
conn.close();
}
}
}
这是以前写的3中数据库的链接已经测试过了。
