public ResultSet getCourse( ){
String sql="select course.name "+
"from classes,course "+
"where classes.tea_id='"+id+"' "+
"and course.id=classes.cour_id";
sqlBean sqlbean = new sqlBean();
ResultSet rs = sqlbean.executeQuery(sql);
return rs;
}
public boolean hasLogin(String id){ //检查该教师是否已经注册
boolean f=true;
String sql="select id from teacher where id ='"+id+"'";
sqlBean db =new sqlBean();
try{
ResultSet rs=db.executeQuery(sq
