title: Oracle script not generating an error, despite incorrect syntax
body: <p>I have written a migration script for a table.  I tested it and ran it on a cloned database (db2) and it was successful, sqldeveloper also reported no issues. However, <em>this script included a syntax error on the insert statement and should have failed;</em> It failed on the db1 instance of my database (correctly) - these databases are identical copies, although stored on different hardware in different locations. I identified the error as a field in the insert statement, that should have been left NULL as it was replacing value xyz with abc.  (Basically a rename)</p>
  
  <p>Extract of the migration script below:</p>
  
  <pre><code>INSERT INTO EXAMPLE_A
  SELECT
  B_VAL_EXAMPLE_LRB,
  NULL,           --B_NEW_VAL1_YN,
  NULL,           --B_NEW_VAL2_YN,
  NULL,                       --Location for B_OTHER_ABC_SPECIFY
  B_PROGRAM_ID,
  --After
  A_VAL_EXAMPLE_LRB,
  NULL,           --A_NEW_VAL1_YN,
  NULL,           --A_NEW_VAL2_YN,
  NULL,                       --Location for A_OTHER_ABC_SPECIFY
  A_PROGRAM_ID
  FROM EXAMPLE_A_BAK;
  </code></pre>
  
  <p>The above example works as it should and works on both db instances.
  The below example works on the database with no data on the table (db2), but not on the db with data (db1) - maybe this is my issue?  <strong>I need to try to explain and understand why the script with the error was able to be ran into an instance of the database without producing an error.</strong></p>
  
  <pre><code>INSERT INTO EXAMPLE_A
  SELECT
  B_VAL_EXAMPLE_LRB,
  NULL,           --B_NEW_VAL1_YN,
  NULL,           --B_NEW_VAL2_YN,
  B_OTHER_ABC_SPECIFY,        --Location for B_OTHER_ABC_SPECIFY
  B_PROGRAM_ID,
  --After
  A_VAL_EXAMPLE_LRB,
  NULL,           --A_NEW_VAL1_YN,
  NULL,           --A_NEW_VAL2_YN,
  A_OTHER_ABC_SPECIFY,        --Location for A_OTHER_ABC_SPECIFY
  A_PROGRAM_ID
  FROM EXAMPLE_A_BAK;
  </code></pre>
  
  <p>Is it possible different versions of sqldeveloper - or even an issue with oracle parsing the query could be the explanation?</p>
  
  <p>Maybe I've been looking at this too long and have ironically overlooked something, but any help would be great.  The only differences between the two instances of the same database are that db1 has data already in the table before I attempt the migration.</p>