String sql="select*from user where name=? and pwd=?";
PrepareStatement pstm=conn.prepareStatement(sql);
pstm.setString(1,"name");
pstm.setInt(2."pwd");
ResultSet rs= pstm.executeQuery();
String sql="select*from user where name=? and pwd=?";
User u=new User();
String name=u.setName("zhangsan");
int pwd=u.setPwd(123);
Object[] obj={name,pwd};
PrepareStatement pstm=conn.prepareStatement(sql);
ResultSet rs=null;
for(int i =0;i<obj.length;i++){
pstm.setObject(i+1,obj[i]);
}
rs=pstm.executeQuery(); //查询返回ResultSet
}
String sql="delete from user where id=? ";
User u=new User();
int id=u.setid(123);
Object[] obj={id};
PrepareStatement pstm=conn.prepareStatement(sql);
for(int i =0;i<obj.length;i++){
pstm.setObject(i+1,obj[i]);
}
int i=pstm.executeUpdate(); //增删改 返回int
}
HttpSession session= request.getSession();//创建session
session.setSession("name","张三");//赋值
session.getSession(name);//取值
