powerdao.java

应用struts技术开发的java的多表关系的增删改应用程序

package com.xaccp.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.List;
import java.util.Vector;

import com.xaccp.db.DBManager;
import com.xaccp.vo.EmpVo;
import com.xaccp.vo.PowerVo;

public class PowerDao {
	/**
	 * 该类为员工待遇的dao
	 */

	/**
	 * 获得所有待遇信息
	 */
	public List getAll(){
		//1 连接
		Connection con=DBManager.getConnection();
		//2 sql
		String sql="select * from power order by powerId";
		try {
			//3 execute sql
			Statement st=con.createStatement();
			ResultSet rs=st.executeQuery(sql);
			
			List pvo=new Vector();
			while(rs.next()){
				
				PowerVo powervo=new PowerVo();
				
				powervo.setPowerId(rs.getInt("powerId"));
				powervo.setPowerName(rs.getString("powerName"));
				
				pvo.add(powervo);
			}
			rs.close();
			st.close();
			con.close();
			return pvo;
		} catch (SQLException e) {
			// TODO 自动生成 catch 块
			e.printStackTrace();
			return null;
		}
	}
	
	/**
	 * 删除关系表中的信息
	 */
	public void delEmp_Power(int empId){
		//1 连接
		Connection con=DBManager.getConnection();
		//2 sql
		String sql="delete from emp_power where empId=?";
		try {
			//3 execute sql
			PreparedStatement ps=con.prepareStatement(sql);
			ps.setInt(1,empId);
			ps.executeUpdate();
			ps.close();
			con.close();
		} catch (SQLException e) {
			// TODO 自动生成 catch 块
			e.printStackTrace();
		}
	}
	
	/**
	 * 添加关系表中的信息
	 */
	public void addEmp_Power(EmpVo empVo){
		//1 连接
		Connection con=DBManager.getConnection();
		//2 sql
		String sql="insert into emp_power values(?,?)";
		try {
			//3 execute sql
			PreparedStatement ps=con.prepareStatement(sql);
			List list=empVo.getPowers();
			for (int i = 0; i < list.size(); i++) {
				ps.setInt(1,empVo.getEmpId());
				ps.setInt(2,((PowerVo)empVo.getPowers().get(i)).getPowerId());
				ps.executeUpdate();
			}
			ps.close();
			con.close();
		} catch (SQLException e) {
			// TODO 自动生成 catch 块
			e.printStackTrace();
		}
	}
}