$result = mysql_query(" select Name_Sc,Name_Tc,Requirement.ID_Sc,Requirement.ID_Tc
from School,Teacher,Requirement
where School.ID_Sc = Requirement.ID_Sc and Teacher.ID_Tc = Requirement.ID_Tc and Requirement.Re_Status = 'connect' EXCEPT
select Name_Sc,Name_Tc,Requirement.ID_Sc,Requirement.ID_Tc
from School,Teacher,Requirement,Promise
where School.ID_Sc = Requirement.ID_Sc and Teacher.ID_Tc = Requirement.ID_Tc and Requirement.Re_Status = 'connect' and Requirement.ID_Sc = Promise.ID_Sc and Requirement.ID_Tc = Promise.ID_Tc")or die(mysql_error());
$result = mysql_query(" select Name_Sc,Name_Tc,Requirement.ID_Sc,Requirement.ID_Tc
from School,Teacher,Requirement
where School.ID_Sc = Requirement.ID_Sc and Teacher.ID_Tc = Requirement.ID_Tc and Requirement.Re_Status = 'connect' not in
(select Name_Sc,Name_Tc,Requirement.ID_Sc,Requirement.ID_Tc
from School,Teacher,Requirement,Promise
where School.ID_Sc = Requirement.ID_Sc and Teacher.ID_Tc = Requirement.ID_Tc and Requirement.Re_Status = 'connect' and Requirement.ID_Sc = Promise.ID_Sc and Requirement.ID_Tc = Promise.ID_Tc)")or die(mysql_error());