connectiondb.java

用eclipse编写的图书管理系统

package sever.db;
import java.sql.*;

public class ConnectionDB {
	 public Connection con;//连接
     public  Statement st;//执行SQL语句
     public ResultSet rs;//查询结果集
     int count;//影响行数
     
     //连接数据库
    public Connection connectionTo(){
     try{
          Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
          con=DriverManager.getConnection("jdbc:odbc:tin");

     }catch(Exception e){
      System.out.println("数据库连接失败！");
     }
     return con;
    }
   
 //执行数据库查询
public ResultSet queryData(String sql){
          try{
         con=connectionTo();
         st=con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
         rs=st.executeQuery(sql);
             }catch(SQLException a){
             System.out.println("数据查询出错！");
          }

           return rs;

        }
   
    
    //执行数据更新
    public int updateData(String sql){
    try{
         con=connectionTo();
         st=con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE);
         count=st.executeUpdate(sql);
         con.close();
    }catch(SQLException a){
     System.out.println("数据更新出错！");
    }

    return count;
  }
}