title: Oracle SQL Developer treats my comment as a command
body: <p>I've created some very basic SQL script:</p>
  
  <pre><code>/*
    Change date format
  */
  alter session set nls_date_format='DD/MM/YYYY';
  
  /*
    Drop old tables (if exists)
  */
  DROP TABLE Students;
  
  /*
    Create new tables
  */
  CREATE TABLE Students
    (
      Id NUMBER(6) PRIMARY KEY,
      LastName VARCHAR2(20),
      FirstName VARCHAR2(10),
      Address VARCHAR2(10),
      BirthDay DATE,
      GroupId NUMBER(3)
    );
  
  /*
    Check the table was created successfully
  */
  DESC Students;
  
  /*
    Insert a new record to the table
  */
  INSERT INTO Students VALUES(101, 'Solin', 'Dan', 'Beer-Sheva', '01/02/1985', 11);
  
  /*
    Check the record was inserted succesfully
  */
  SELECT * FROM Students;
  
  /*
    Add 'AvgMark' field to the table with default of 0
  */
  ALTER TABLE Students ADD AvgMark NUMBER(5,2) DEFAULT 0;
  
  /*
    Check that the new field was added
  */
  DESC Students; 
  
  /*
    Insert 3 new records to the table
  */
  INSERT INTO Students VALUES(102, 'Tal', 'Ruti', 'Tel-Aviv', '10/07/1988', 12, 70);
  INSERT INTO Students VALUES(103, 'Kohen', 'Yossi', 'Dimona', '01/08/1987', 11, 80);
  INSERT INTO Students VALUES(104, 'Toys', 'Vered', 'Tel-Aviv', '15/09/1988', 12, 90);
  
  /*
    Check the records were inserted succesfully
  */
  SELECT * FROM Students;
  
  /*
    Change 'Address' data type to VARCHAR2(15)
  */
  ALTER TABLE Students MODIFY Address VARCHAR2(15);
  
  /*
    Check that the data type has changed
  */
  DESC Students; -- Some comment
  </code></pre>
  
  <p>At the end of the <code>Script Output</code> i get this Error Message:
  <code>ERROR: object COMMENT does not exist</code></p>
  
  <p>If i'll change the comment to <code>Hello World</code> i'll get the same error for <code>WORLD</code> "object"...</p>
  
  <p>I changed the whole script to avoid single line comments, and the result is the same.</p>
  
  <p>I could avoid it again in this example but i really want to understand what's causing this weird problem...</p>
  
  <hr>
  
  <p>Another thing which might help solving the issue, is another weird error i have in the same script, few lines above the comment. in this line: 
  <code>ALTER TABLE Students MODIFY Address VARCHAR2(15);</code></p>
  
  <p>SQL Developer shows me an error under the last two characters (the right parenthesis and the semicolon) saying <code>Syntax error. Partially recognized rules (Railroad diagrams): ...</code></p>
  
  <p>If i'll run the statement it'll work just fine...</p>