querybooks.java

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package ksnb;

import javax.sql.rowset.*;
import java.sql.*;
import java.util.*;
import javax.servlet.http.*;
public class Querybooks {

    private Statement st;
    private ResultSet rs;
    private Connection con;
    SQL_odbc db = new  SQL_odbc();


    public Querybooks() {
        try{
            con=db.connect();    //接收user_odbc中connect的返回值
            st=con.createStatement();
            System.out.println("Querybooks.java 提示：连接数据库成功！");
        }
        catch(Exception e)
        {
            System.out.println("Querybooks.java 提示：连接数据库出现错误！！！");
            System.out.println("错误原因："+e.getMessage());
            this.close();
        }
    }

    public ResultSet query(String sql)
    {
        try
        {
            rs = st.executeQuery(sql);
        }
        catch(Exception e)
        {
            System.out.println(e.toString());
        }
        return rs;

    }


    public void close()
      {
          db.close();
    }

}