title: Invalid identifier Oracle SQL Dev
body: <p>I have a stupid problem, I know, but I don't see my error(s)...</p>
  
  <p>Here is my SQL code when I create my tables</p>
  
  <pre><code>CREATE TABLE Nageur
  (   NumN number not null,
      NomN varchar2(30) null,
      PrenomN varchar2(30) null,
      AnDateNaiss number null, 
      Nationalite varchar2(10),
      Genre varchar2(1),
      Pole varchar2(50),
          CONSTRAINT PK_Nageur PRIMARY KEY (NumN));
  
      CREATE INDEX I_FK_Nageur_Club
          ON Nageur (NumClub ASC);
  
  CREATE TABLE Club
  (   NumClub number NOT NULL,
      NomClub varchar2(40) NULL, 
      Region varchar2(40) NULL,
      Departement varchar2(40) NULL, 
          CONSTRAINT PK_Club PRIMARY KEY (NumClub));
  </code></pre>
  
  <p>The lines that gives me errors</p>
  
  <pre><code>ALTER TABLE Nageur ADD (
  CONSTRAINT FK_nageur_club
  FOREIGN KEY (NumClub)
  REFERENCES Club (NumClub));
  
  ALTER TABLE Competition ADD (
  CONSTRAINT FK_competition_piscine
  FOREIGN KEY (NumP)
  REFERENCES Piscine (NumP));
  </code></pre>
  
  <p>And here my errors on Oracle</p>
  
  <pre><code>Erreur commençant à la ligne: 97 de la commande -
  ALTER TABLE Nageur ADD (
  CONSTRAINT FK_nageur_club
  FOREIGN KEY (NumClub)
  REFERENCES Club (NumClub))
  Rapport d'erreur -
  Erreur SQL : ORA-00904: "NUMCLUB" : identificateur non valide
  00904. 00000 -  "%s: invalid identifier"
  *Cause:    
  *Action:
  
  Erreur commençant à la ligne: 102 de la commande -
  ALTER TABLE Competition ADD (
  CONSTRAINT FK_competition_piscine
  FOREIGN KEY (NumP)
  REFERENCES Piscine (NumP))
  Rapport d'erreur -
  Erreur SQL : ORA-00904: "NUMP" : identificateur non valide
  00904. 00000 -  "%s: invalid identifier"
  *Cause:    
  *Action:
  </code></pre>
  
  <p>And I don't see my error because NumClub and NumP exist...</p>