title: Oracle JSON column results in invalid identifier when used in a join
body: <p>I've got an Oracle (12c) database as follows:</p>
  
  <pre><code>create table t1 (
      id number, tags clob, constraint t1_chk check ( tags is json) enable
  );
  create table t2 (id number);
  
  create or replace view v1 as 
  select ta.id, ta.tags from t1 ta
  join t1 tb on ta.id=tb.id;
  </code></pre>
  
  <p>This creates two tables (t1 and t2), and a view (v1) of t1 joined to itself.</p>
  
  <p>When I do some queries on the json column in t1 or v1, the query works as expected:</p>
  
  <pre><code> select t.id, t.tags.foo from t1 t;
   select t.id, t.tags.foo from v1 t;
  </code></pre>
  
  <p>Since I haven't bothered in this example to populate the tables, no rows are returned, but the query works as expected and returns empty rows with two columns, ID and FOO.</p>
  
  <p>However, if I try to join t2, then the query fails with an ORA-00904 invalid identifier error:</p>
  
  <pre><code> select t.id, t.tags.foo, x.id from v1 t
   join t2 x on x.id = t.id
  
  ORA-00904: "T"."TAGS"."FOO": invalid identifier
  00904. 00000 -  "%s: invalid identifier"
  *Cause:    
  *Action:
  Error at Line: 55 Column: 15
  </code></pre>
  
  <p>Does anyone have any suggestions as to how to get a join like this to work with the json column?</p>