bookservice.java

因为是初学所以做得不是很完善 希望大家见谅

package service;

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

public class bookservice {
	String driver="com.microsoft.jdbc.sqlserver.SQLServerDriver"; 
	String url="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=books";
	String user="sa"; String passwd="123";
	Connection con=null; ResultSet rs=null; Statement st=null;


	public void connect(){
	try{
	Class.forName(driver);
	con=DriverManager.getConnection(url,user,passwd);
	}catch(Exception e){  System.out.println(e.toString());}
	}
   
	//列出书籍信息
	public ResultSet list(){
	if(con==null)
		connect();
	String sql="select * from book";
	
	try{
		st=con.createStatement();
		rs=st.executeQuery(sql);}
	catch(Exception ex){
			System.out.println(ex.toString());
		}
	return rs;
 	}
	
	
	//删除书籍信息
    public void Del(int id)
    {
    	//System.out.println("你好");
    	if(con==null)
    		connect();
    	String sql="delete from book where book_ID="+id;
    	try{
    		st=con.createStatement();
    		st.executeUpdate(sql);
    	}catch(Exception e){System.out.println("无法删除"+e.toString());}
    }
    
    
    //更新书籍信息
    public void Update(String bid,String bname,String bauthor,String bpublish,String bprice,int id)
    {
    	
    	
    	if(con==null)
    		connect();
    	String sql="update book set book_ID='"+bid+"',name='"+bname+"',author='"+bauthor+"',publish='"+bpublish+"',price='"+bprice+"'where book_ID="+id;
    	
    	try{
    		st=con.createStatement();
    		st.executeUpdate(sql);
    	}catch(Exception e){System.out.println("无法修改图书信息"+e.toString());}
    }
    
    //添加书籍信息
    public void AddBook(String bid,String bname,String bauthor,String bpublish,String bprice)
    {
    	
    	if(con==null)
    		connect();
    	String sql="insert into book values('"+bid+"','"+bname+"','"+bauthor+"','"+bpublish+"','"+bprice+"')";
    	try{
    		st=con.createStatement();
    		st.executeUpdate(sql);
    		
    	}catch(Exception e){System.out.println("添加信息不成功"+e.toString());}
    }

    
   
    
    
	public void close()
	{
		try{
		if(rs!=null)
			rs.close();
		}catch(Exception e){System.out.println("无法关闭SQL连接"+e.toString());}
	}
}