database.java

管理员及学生身份 图书检索与图书插入删除

/*
 * Database.java
 *
 * Created on 2007年12月26日, 上午8:45
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */
package book;
import book.*;
import java.sql.*;
import java.util.*;
import javax.swing.JOptionPane;
import javax.swing.JTable;

public class Database {
    Connection con;
    Statement stmt;
    ResultSet rs;
   
    public Database() { }
    
    public String link() {
        String rturn="";
        try{
            Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
            con=DriverManager.getConnection("jdbc:odbc:qs");
            stmt=con.createStatement();
            rturn="y";
        } catch(Exception e){
            JOptionPane.showMessageDialog(null,"链接出错");
            rturn=e.toString();
        }
        return rturn;
    }
    public void cutlink() {
        try{
            if(con!=null){
                con.close();
                con=null;
            }
        }
        catch(Exception e){}
    }
    
    public ResultSet getResult(String sql){
        try{
            rs=stmt.executeQuery(sql);
            return rs;
        }catch(SQLException e){
            return null;
        }        
    }
   public String add_book(String[] add){
       String f="";
       try{
           link();
           String sql="select count(*) from book_jbxx";
           rs=stmt.executeQuery(sql);
           rs.next();
           if(rs.getInt(1)>0){
               sql="select max(*) from book_jbxx";
                rs=getResult(sql);
           }
          sql="insert into book_jbxx values ('"+add[0]+"','"+add[1]+"','"+add[2]+"','"+add[3]+"','"+add[4]+"','"+add[5]+"')";
          stmt.execute(sql);
          f="y";
       }
        catch(Exception e){
            JOptionPane.showMessageDialog(null,"没有此分类！"+f);
        }
        finally{
            cutlink();
        }
       return f;
   }
 
   public static void main(String[] args) {
       String s="";
       try{
       Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
       Connection con=DriverManager.getConnection("jdbc:odbc:qs");
       Statement stmt=con.createStatement();
       ResultSet rs=stmt.executeQuery("select * from book_classify");rs.close();
       stmt.close();
       con.close();
       //System.out.println("----------------------------------------");测试语句
     }catch(ClassNotFoundException e){
         System.out.println(""+e.toString());
        System.out.println("Nofound");
     }catch(SQLException e){
        System.out.println("SQL error:"+e);
     }
   }
}