sharedao.java

07年做得人力资源管理系统

package com.buat.hr.share;

import java.sql.Connection;
import java.sql.Date;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;

public abstract class ShareDAO  implements IShareDAO{
	protected DBConnection db=new DBConnection();	
	
	//根据Id删除表中信息
	public boolean deleteByid(String tableName,int id) {   
		boolean flag=false;
		Connection con=null;
		PreparedStatement ps=null;
		String str=null;
		
		con=db.getConnection();
		str="delete from "+tableName+" where id="+id;
		try {
			ps=con.prepareStatement(str);
			ps.executeUpdate();			
			flag=true;
			
		} catch (SQLException e) {
			flag=false;
		}finally{
			try {
				if(ps!=null){
					ps.close();
				}
				if(con!=null){
					con.close();
				}
			} catch (SQLException e) {
			}
		}
		return flag;
	}

	public boolean deleteByid(String id,String tableName,String colName) {   
		boolean flag=false;
		Connection con=null;
		PreparedStatement ps=null;
		String str=null;
		int row=0;
		
		con=db.getConnection();
		str="delete from "+tableName+" where "+colName+"="+id;
		System.out.print("sql="+str.toString());
		try {
			ps=con.prepareStatement(str);
			row=ps.executeUpdate();
			
			if(row>0){
				flag=true;
			}
		} catch (SQLException e) {

		}finally{
			try {
				if(ps!=null){
					ps.close();
				}
				if(con!=null){
					con.close();
				}
			} catch (SQLException e) {

			}
		}
		return flag;
	}

/*
 *  作用：向表中添加记录
 * 	注：
 * 		sql——用于保存新增记录的sql语句	
 * 
 *      str——保存sql语句
 *      
 *      flag——用语判断删除是否成功 
 *              true:删除成功 
 *  
 */	
	public boolean add(String sql) {  
		boolean flag=false;
		Connection con=null;
		PreparedStatement ps=null;
		
		con=db.getConnection();
		try {
			ps=con.prepareStatement(sql);
			ps.executeUpdate();	
			flag=true;

		} catch (SQLException e) {
			flag=false;
		}finally{
			try {
				if(ps!=null){
					ps.close();
				}
				if(con!=null){
					con.close();
				}
			} catch (SQLException e) {
			}
		}
		return flag;
	}	

/*
 * 作用：修改表中记录
 * 注:
 * 		sql——用于保存新增记录的sql语句	
 *  	flag——用语判断删除是否成功 
 *              true:删除成功 
 * 
 */
	public boolean update(String sql) {      
		boolean flag=false;
		Connection con=null;
		PreparedStatement ps=null;
		
		con=db.getConnection();
		try {
			ps=con.prepareStatement(sql);
			ps.executeUpdate();			
			flag=true;
		
		} catch (SQLException e) {
			flag=false;
		}finally{
			try {
				if(ps!=null){
					ps.close();
				}
				if(con!=null){
					con.close();
				}
			} catch (SQLException e) {
			}
		}
		return flag;
	}
	//得到表中总数
	public int getCount(String sql) {        
		int count=0;
		Connection con=null;
		PreparedStatement ps=null;
		ResultSet rs=null;
		
		con=db.getConnection();
		try {
			ps=con.prepareStatement(sql);
	
			rs=ps.executeQuery();
			while(rs.next()){
				count=rs.getShort(1);
			}
		} catch (SQLException e) {
		}finally{
			try {
				if(rs!=null){
					rs.close();
				}
				if(ps!=null){
					ps.close();
				}
				if(con!=null){
					con.close();
				}
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
		return count;
	}
	public Date Time(){    //得到系统时间
		Connection con=null;
		PreparedStatement ps=null;
		ResultSet rs=null;
		String sql="select current_date() as date";
		con=db.getConnection();

		try {
			ps = con.prepareStatement(sql);
			rs = ps.executeQuery();
			rs.next();
			String date=rs.getString("date");
			
			return Date.valueOf(date);
		}catch(Exception e){return null;}
	
	}
	public abstract ArrayList query(int startNo, int perCount, String tableName);        //查询部分记录(用于分页)
	
	
}