求jsp学生管理 MyEclipse+Tomcat+sql server2005,实现学生的增，删，改，查管理等功 需要Dao+servlet。

String bs_id = request.getParameter("bs_id");
if(bs_id!=null)
{
BranchSchool_Dao d=new BranchSchool_Dao();
String a=null;
a="bs_id="+Integer.parseInt(bs_id);
d.Select_Simple_BranchSchool(a);
报最后一行错误，取出值了是bs_id=2，

rs = st.executeQuery(sql1);//这行也报错了
String sql1="select * from BranchSchool where "+sql;
DataBase_connection con=new DataBase_connection();
ResultSet rs=con.executeSQL(sql1); //这行也报错了
BranchSchool people=new BranchSchool();