poll_dao.java

这是一个Struts网上商城(图书)的管理系统源代码.

package com.bookshop.dao;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import com.bookshop.db.DBConnection;
import com.bookshop.dto.bbs_dto;
import com.bookshop.dto.bookinfo_dto;
import com.bookshop.dto.poll_dto;

public class poll_dao {
	//添加投票
	public int poll_select(String optionname)
	{
		ArrayList list = new ArrayList();
		Connection conn =null;
		conn=DBConnection.getConnection();
		Statement st = null;
		ResultSet rs = null;
		String strSQL=null;
		String strSQL2=null;
		int n=0;
		int poll=0;
		poll_dto newpoll=new poll_dto();
		try {
			st = conn.createStatement();
			strSQL="SELECT  * FROM tb_poll where optionname='"+optionname+"'";
			rs = st.executeQuery(strSQL);
			if (rs.next())
			poll=Integer.parseInt(rs.getString("poll"))+1;
			strSQL2="update tb_poll set poll="+poll+" where optionname='"+optionname+"'";
			n=st.executeUpdate(strSQL2);
			System.out.print(strSQL2);
		} catch (SQLException e) {
			e.printStackTrace();
			
		}
		finally
		{
    	 try {
    	        rs.close();
    	        st.close();
    	        conn.close();
    	    } catch (SQLException ex1) {
    	        ex1.printStackTrace();
    	    }    	
	    }				
		return n;
	}
	//查询详情
	public ArrayList po_select()
	{
		Connection conn=DBConnection.getConnection();
		ArrayList list =new ArrayList();
		Statement st=null;
		ResultSet rs=null;
		String sql="";
		try{
			sql="select * from tb_poll";
			st=conn.createStatement();
			rs=st.executeQuery(sql);
			while(rs.next())
			{
				poll_dto newpoll=new poll_dto();
				newpoll.setId(rs.getString("id"));
				newpoll.setOptionname(rs.getString("optionname"));
				newpoll.setPoll(rs.getString("poll"));
				list.add(newpoll);								
			}				
		}catch(SQLException e){e.printStackTrace();}
		finally{
			try{
				rs.close();
				st.close();
				conn.close();
			}catch(SQLException e){e.printStackTrace();}
		}
		return list;
	}
	
	//查询单条信息
	
	public poll_dto select(String id){
		Connection conn =DBConnection.getConnection();
		Statement st = null;
		ResultSet rs = null;
		poll_dto dto=new poll_dto();
		String sql="select * from tb_poll where id="+id;
		try{
			st=conn.createStatement();
			rs=st.executeQuery(sql);
			if(rs.next()){
				dto.setId(rs.getString("id"));
				dto.setOptionname(rs.getString("optionname"));
				dto.setPoll(rs.getString("poll"));
			}
			
		}catch(SQLException e){e.printStackTrace();}
		finally{
			try{
				rs.close();
				st.close();
				conn.close();
			}catch(SQLException e){e.printStackTrace();}
		}
		return dto;
	}
   //删除投票信息
	
	public int delete(String id){
		Connection conn =DBConnection.getConnection();
		Statement st = null;
		String sql="";
		int n=0;
		try{
			sql="delete from tb_poll where id="+id;
			st=conn.createStatement();
			n=st.executeUpdate(sql);
		}catch(SQLException e){e.printStackTrace();}
		finally{
			try{
				
				st.close();
				conn.close();
			}catch(SQLException e){e.printStackTrace();}
		}
		return n;
		
		
	}
	//添加投票信息
	public int add(String optionname){
		Connection conn =DBConnection.getConnection();
		Statement st = null;
		String sql="";
		
		int n=0;
		try{
			sql="insert into tb_poll (optionname) values('"+optionname+"')";
			st=conn.createStatement();
			n=st.executeUpdate(sql);
		}catch(SQLException e){e.printStackTrace();}
		finally{
			try{
				st.close();
				conn.close();
			}catch(SQLException e){e.printStackTrace();}
		}
		
		return n;
		
		
		
	}

}