goodsdb.java

这是个简单的在线书店购书系统

package mypack;
import java.sql.*;
import java.util.*;
import java.lang.*;
public class GoodsDB{
		 
  String driver="com.microsoft.jdbc.sqlserver.SQLServerDriver";
  String user="sa";
  String pwd="sa";
  String url="jdbc:microsoft:sqlserver://127.0.0.1;databaseName=lm";
  private Connection con;
private Connection getCon() {
	try{
		 Class.forName(driver);
		 Connection con=DriverManager.getConnection(url, user, pwd);
 		return con;
	}catch(Exception e){
		e.printStackTrace();
	}
	return null;
}
public boolean  addcar(int userid,int bookid){
	try{
		
		   Connection con=getCon();
		   String sql="insert goods (userid,bookid) values('"+userid+"','"+bookid+"')";
   		   Statement stm=con.createStatement();
		   int flg=stm.executeUpdate(sql);
			if(flg!=0){return true;}
			}catch(Exception e){
				e.printStackTrace();
					}
			return false;
		    	
	}
public ResultSet getcar(int userid){
		try{
		
		   Connection con=getCon();
		   String sql="select books.bookname books.author books.pub books.price books.sortname from books  where bookid in  (select bookid from goods where goods.userid='"+userid+"') ";
			Statement stm=con.createStatement();
			ResultSet rs=stm.executeQuery(sql);
		         if(rs.next()){
			    return rs;}
			}catch(Exception e){
				e.printStackTrace();
					}
			return null;
	}
}