//package itstudy;

import java.sql.*;

public class dbLian
{
	private Connection conn = null;
	private Statement stmt = null;
	private String dbString = "com.microsoft.jdbc.sqlserver.SQLServerDriver";
	private String url = "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=GuestBook";
	private String user = "GuestBook"; 
	private String password = "GuestBook"; 

	public dbLian()
	{
		try
		{
	        Class.forName(dbString);
	    }
	    catch(ClassNotFoundException e)
	    {
			System.out.println(e.getMessage());
		}	
	}
	
	public ResultSet executeQuery(String sql)
	{
		try
		{
	        conn = DriverManager.getConnection(url,user,password);
	        stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE ,ResultSet.CONCUR_READ_ONLY);
			ResultSet rs=stmt.executeQuery(sql);
			return rs;			
		}
	    catch(SQLException e)
		{
		   System.out.println(e.getMessage());
		}
		return null;		
	}
	
	public int executeDelete(String sql)
	{
		try
		{
	        conn = DriverManager.getConnection(url,user,password);
	        stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE ,ResultSet.CONCUR_READ_ONLY);
			int tiao=stmt.executeUpdate(sql);
			return tiao;			
		}
	    catch(SQLException e)
		{
		   System.out.println(e.getMessage());
		}
		return 0;		
	}
		
	public int executeInsert(String sql)
	{
		try
		{
	        conn = DriverManager.getConnection(url,user,password);
	        stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE ,ResultSet.CONCUR_READ_ONLY);
			int tiao=stmt.executeUpdate(sql);
			return tiao;	
		}
	    catch(SQLException e)
		{
		   System.out.println(e.getMessage());
		}
		return 0;		
	}
	
	public int executeUpdate(String sql)
	{
		try
		{
	        conn = DriverManager.getConnection(url,user,password);
	        stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE ,ResultSet.CONCUR_READ_ONLY);		
			int tiao=stmt.executeUpdate(sql);
			return tiao;			
		}
	    catch(SQLException e)
		{
		   System.out.println(e.getMessage());
		}
		return 0;		
	}
	
	public Connection getConn()
	{
		try
		{
	        conn = DriverManager.getConnection(url,user,password);
	        return conn;		
		}
	    catch(SQLException e)
		{
		   System.out.println(e.getMessage());
		}		
		return null;
	}
}