DAO 操作数据库

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package dao;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.SQLException;

import javax.resource.cci.ResultSet;

import po.Customer;

public class CustomerDao {

private Connection conn = null;

// 连接数据库

private void initConnection() {

try{

Class.forName("oracle.jdbc.driver.OracleDriver");

}

catch(ClassNotFoundException e)

{

System.out.println("数据库驱动类没找到");

}

try {

// 建立连接

String serverName = "127.0.0.1";

String portNumber = "1521";

String sid = "oracle";

String url = "jdbc:oracle:thin:@" + serverName + ":" + portNumber + ":" + sid;

String username = "scott";

String password = "tiger";

conn = DriverManager.getConnection(url, username, password);

System.out.println("数据库连接成功！");

} catch (SQLException e) {

System.out.println("执行SQL语句异常！");

e.printStackTrace();

}

// 插入数据

public boolean insertCustomer(Customer cus) {

String sql = "INSERT INTO T_CUSTOMER(ACCOUNT,PASSWORD,CNAME,CBALANCE)VALUES(1,1,1,1)";

try {

initConnection();

PreparedStatement ps = conn.prepareStatement(sql);

ps.setString(1, cus.getAccount());

ps.setString(2, cus.getPassword());

ps.setString(3, cus.getCname());

ps.setDouble(4, cus.getCbalance());

ps.executeUpdate();

return true;

} catch (Exception ex) {

ex.printStackTrace();

} finally {

closeConnection();

}

return false;

}

// 修改数据

public boolean updateCustomer(Customer cus) {

String sql = "UPDATE T_CUSTOMER SET PASSWORD=?,CNAME=?,CBALANCE=? WHERE ACCOUNT=?";

try {

initConnection();

PreparedStatement ps = conn.prepareStatement(sql);

ps.setString(1, cus.getPassword());

ps.setString(2, cus.getCname());

ps.setDouble(3, cus.getCbalance());

ps.setString(4, cus.getAccount());

ps.executeUpdate();

} catch (Exception ex) {

ex.printStackTrace();

} finally {

closeConnection();

}

return false;

}

// 查询数据

public Customer getCustomer(String account) {

String sql = "SELECT ACCOUNT,PASSWORD,CNAME,CBALANCE FROM T_CUSTOMER WHERE ACCOUNT=?";

try {

initConnection();

PreparedStatement ps = conn.prepareStatement(sql);

ps.setString(1, account);

ResultSet rs = (ResultSet) ps.executeQuery();

if (rs.next()) {

Customer cus = new Customer();

cus.setAccount(rs.getString("ACCOUNT"));

cus.setPassword(rs.getString("PASSWORD"));

cus.setCname(rs.getString("CNAME"));

cus.setCbalance(rs.getDouble("CBALANCE"));

return cus;

}

} catch (Exception ex) {

ex.printStackTrace();

} finally {

closeConnection();

}

return null;

}

// 断开连接

public void closeConnection() {

try {

if (conn != null) {

conn.close();

conn = null;

}

} catch (Exception ex) {

ex.printStackTrace();

}