package com.book.util;

import java.sql.*;

public class JdbcDemo{
public static void main(String args[]){
int pty;
float cost;
String book;
String bookid;
String query = "SELECT Name, Description,Qty,Cost FROM Stock";

try{
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
Connection con = DriverManager.getConnection(
"jdbc:microsoft:sqlserver://127.0.0.1","sa","sa");
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM book where bookid = 001");
while (rs.next()){

System.out.println(rs.getString("bookid"));
}
con.close();
}
catch(ClassNotFoundException e){
e.printStackTrace();
}
catch(SQLException e){
e.printStackTrace();
}
}
}

你有没有 SQL驱动程序的.jar文件阿？
如果你没导入的话，你这样做事连不上数据库的。
还有
Connection con = DriverManager.getConnection("jdbc:microsoft:sqlserver://127.0.0.1","sa","sa");
好像有问题
你把括号内的内容改成
"jdbc:microsoft:sqlserver://1433:127.0.0.1;databaseName=pubs","sa","sa"
你在试试，“databaseName=pubs”pubs应该是你连接的数据库的名字。