java连接Oracle数据库

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Oracle数据库先创建一个表和添加一些数据

1.先在Oracle数据库中创建一个student表:

 create table student
 (
        id number(11) not null primary key,
        stu_name varchar(16) not null,
        gender number(11) default null,
        age number(11) default null,
        address varchar(128) default null
 );

2.向表中增添一些数据

insert into student values('','王小军','','','北京市和平里七区30号楼7门102')

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MyEclipse里编写java代码

1.将ojdbc6.jar导入项目中

先创建一个项目，然后在鼠标移到项目上右键-->new-->folder;folder name:lib;这样就在项目中创建了一个文件夹lib;然后将ojdbc6.jar包导入该文件夹中

该包分享地址:链接：https://pan.baidu.com/s/1jW_ofgU4eJmAn7Y2J5B46A 密码：epkz

鼠标移到该包上;右键-->build path-->add to build path;

2.创建一个类,开始编码

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

public class OperateOracle {

    // 定义连接所需的字符串
    // 192.168.0.X是本机地址(要改成自己的IP地址)，1521端口号，XE是精简版Oracle的默认数据库名
    private static String USERNAMR = "orcl";
    private static String PASSWORD = "orcl";
    private static String DRVIER = "oracle.jdbc.OracleDriver";
    private static String URL = "jdbc:oracle:thin:@192.168.0.X:1521:xe";

    // 创建一个数据库连接
    Connection connection = null;
    // 创建预编译语句对象，一般都是用这个而不用Statement
    PreparedStatement pstm = null;
    // 创建一个结果集对象
    ResultSet rs = null;

    /**
     * 向数据库中增加数据
     * 首先获取表内数据总数,总数+1为新增数据的id值
     * @param stuName:学生姓名
     * @param gender:学生性别,1表示男性,2表示女性
     * @param age:学生年龄
     * @param address:学生住址
     */
    public void AddData(String stuName, int gender, int age, String address) {
        connection = getConnection();
        // String sql =
        // "insert into student values('1','王小军','1','17','北京市和平里七区30号楼7门102')";
        String sql = "select count(*) from student where 1 = 1";
        String sqlStr = "insert into student values(?,?,?,?,?)";
        int count = 0;

        try {
            // 计算数据库student表中数据总数
            pstm = connection.prepareStatement(sql);
            rs = pstm.executeQuery();
            while (rs.next()) {
                count = rs.getInt(1) + 1;
                System.out.println(rs.getInt(1));
            }
            // 执行插入数据操作
            pstm = connection.prepareStatement(sqlStr);
            pstm.setInt(1, count);
            pstm.setString(2, stuName);
            pstm.setInt(3, gender);
            pstm.setInt(4, age);
            pstm.setString(5, address);
            pstm.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            ReleaseResource();
        }
    }

    /**
     * 向数据库中删除数据
     * @param stuName:根据姓名删除数据
     */
    public void DeleteData(String stuName) {
        connection = getConnection();
        String sqlStr = "delete from student where stu_name=?";
        System.out.println(stuName);
        try {
            // 执行删除数据操作
            pstm = connection.prepareStatement(sqlStr);
            pstm.setString(1, stuName);
            pstm.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            ReleaseResource();
        }
    }

    /**
     * 向数据库中修改数据
     * @param stuName:学生姓名,根据此值查询要修改的某行值
     * @param gender
     * @param age
     * @param address
     */
    public void UpdateData(String stuName, int gender, int age, String address) {
        connection = getConnection();
        String sql = "select id from student where 1 = 1 and stu_name = ?";
        String sqlStr = "update student set stu_name=?,gender=?,age=?,address=? where id=?";
        int count = 0;

        try {
            // 计算数据库student表中数据总数
            pstm = connection.prepareStatement(sql);
            pstm.setString(1, stuName);
            rs = pstm.executeQuery();
            while (rs.next()) {
                count = rs.getInt(1);
                System.out.println(rs.getInt(1));
            }
            // 执行插入数据操作
            pstm = connection.prepareStatement(sqlStr);
            pstm.setString(1, stuName);
            pstm.setInt(2, gender);
            pstm.setInt(3, age);
            pstm.setString(4, address);
            pstm.setInt(5, count);
            pstm.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            ReleaseResource();
        }
    }

    /**
     * 向数据库中查询数据
     */
    public void SelectData() {
        connection = getConnection();
        String sql = "select * from student where 1 = 1";
        try {
            pstm = connection.prepareStatement(sql);
            rs = pstm.executeQuery();
            while (rs.next()) {
                String id = rs.getString("id");
                String name = rs.getString("stu_name");
                String gender = rs.getString("gender");
                String age = rs.getString("age");
                String address = rs.getString("address");
                System.out.println(id + "\t" + name + "\t" + gender + "\t"
                        + age + "\t" + address);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            ReleaseResource();
        }
    }

    /**
     * 使用ResultSetMetaData计算列数
     */
    public void SelectData2() {
        connection = getConnection();
        String sql = "select * from employees where 1 = 1";
        int count = 0;

        try {
            pstm = connection.prepareStatement(sql);
            rs = pstm.executeQuery();
            while (rs.next()) {
                count++;
            }

            ResultSetMetaData rsmd = rs.getMetaData();
            int cols_len = rsmd.getColumnCount();

            System.out.println("count=" + count + "\tcols_len=" + cols_len);
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            ReleaseResource();
        }
    }

    /**
     * 获取Connection对象
     *
     * @return
     */
    public Connection getConnection() {
        try {
            Class.forName(DRVIER);
            connection = DriverManager.getConnection(URL, USERNAMR, PASSWORD);
            System.out.println("成功连接数据库");
        } catch (ClassNotFoundException e) {
            throw new RuntimeException("class not find !", e);
        } catch (SQLException e) {
            throw new RuntimeException("get connection error!", e);
        }

        return connection;
    }

    /**
     * 释放资源
     */
    public void ReleaseResource() {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (pstm != null) {
            try {
                pstm.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (connection != null) {
            try {
                connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

3.创建一个测试类

public class Test {

    public static void main(String[] args) {
        /**
         * 增删改查完成,但是有一定局限性
         * 1.增  问题不大
         * 2.删  要给出一个值去删除(可能值不存在-->没有处理机制,值不唯一怎么处理?)
         * 3.改  同删的问题
         * 4.查  问题不大
         */
        //创建OperateOracle对象
        OperateOracle oo=new OperateOracle();
        //测试增加数据操作
        //oo.AddData("孙中山",1,25,"北京市海淀区红旗路111号");
        //测试删除数据操作
        //oo.DeleteData("孙中山");
        //测试更新数据操作
        oo.UpdateData("孙中山",1,30,"北京市东城区岳山路11号");
        //测试查询数据操作
        //oo.SelectData();

        //测试ResultSetMetaData类
        //oo.SelectData2();
    }

}

正如测试类中所注释的,此处只可按照正确的方式去连接Oracle数据库,操作增删改查操作,但是对于一些错误操作的处理机制还不够完善。