title: Why I'm facing this error ORA-02264: name already used by an existing constraint 02264. 00000 - "name already used by an existing constraint" *Cause?
body: <p>Here is my code, can anyone will be fixed this error? I have tried my best to fix this issue but with regret, I get failed. I'm using oracle 11g.</p>
  <pre><code>{  CREATE TABLE ProjectX
    (
       ProjectID int NOT NULL PRIMARY KEY,
       Name VARCHAR(40),
       DepartmentID NUMBER,
  
       CONSTRAINT Department_ID FOREIGN KEY (DepartmentID)
       REFERENCES Department(DepartmentID)
    );
  }
  </code></pre>