JDBC-简单连接Oracle Database

JDBC

The JDBC API is a Java API that can access any kind of tabular data, especially data stored in a Relational Database.

JDBC helps you to write Java applications that manage these three programming activities:

Connect to a data source, like a database

Send queries and update statements to the database。

Retrieve and process the results received from the database in answer to your query

1JDBC - oracle

1.1 Install a JDBC driver from Oracle

现在oracle JDBC驱动器： ojdbc6_g。

将ojdbc6_g放入到项目的lib文件夹中，如下

C:\study\java\jdbc\lib\ojdbc6_g.jar

1.2 eclipse导入驱动器ojdbc6_g

在eclipse中导入如下：

右键点击JDBC项目 ---> Build Path ---> Config Build Path ---> Libraries ---> Add External JARs ---> 输入C:\study\java\jdbc\lib\ojdbc6_g.jar ---> OK

1.3 编写程序测试

package jdbc;

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

public class jdbc_exp {

public static void main(String[] args) {
Connection con = null;// 创建一个数据库连接
PreparedStatement pre = null;// 创建预编译语句对象，一般都是用这个而不用Statement
ResultSet result = null;// 创建一个结果集对象
try
{
Class.forName("oracle.jdbc.driver.OracleDriver");// 加载Oracle驱动程序
System.out.println("开始尝试连接数据库！");
String url = "jdbc:oracle:" + "thin:@0.0.0.188:1521:tonytest";// 127.0.0.1是本机地址，XE是精简版Oracle的默认数据库名
String user = "hr";// 用户名,系统默认的账户名
String password = "CCM%lab123";// 你安装时选设置的密码
con = DriverManager.getConnection(url, user, password);// 获取连接
System.out.println("连接成功！");
String sql = "select * from dept order by 1";// 预编译语句，“？”代表参数
pre = con.prepareStatement(sql);// 实例化预编译语句
result = pre.executeQuery();// 执行查询，注意括号中不需要再加参数
while (result.next())
// 当结果集不为空时
System.out.println("deptno: " + result.getInt("deptno") + " dname: "
+ result.getString("dname") + " loc: " + result.getString("loc")
+ " create_date: " + result.getString("create_date"));
}
catch (Exception e)
{
e.printStackTrace();
}
finally
{
try
{
// 逐一将上面的几个对象关闭，因为不关闭的话会影响性能、并且占用资源
// 注意关闭的顺序，最后使用的最先关闭
if (result != null)
result.close();
if (pre != null)
pre.close();
if (con != null)
con.close();
System.out.println("数据库连接已关闭！");
}
catch (Exception e)
{
e.printStackTrace();
}
}

}

}