JDBC简单连接Oracle详解编程语言

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

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:@10.224.188.188:1521: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(); 
            } 
        } 
 
    } 
 
}