find column names and table names referenced in SQL

Question

How to find all the tables and column names used in a SQL? It is on ORACLE database. Below is an SQL example.

SELECT 
   A.ENAME,
   A.AGE as EMP_AGE,
   B         


        

Answer 1

What I have realised is that this solution will not give you the projected columns, so it may not totally need you needs; it only gives you the columns used in predicates

select
  r.name owner
, o.name tabl 
, c.name colmn
from
sys.col_usage$ u,
sys.obj$ o,
sys.col$ c,
sys.user$ r
where
r.name='&scahme' and
o.obj# = u.obj#
and c.obj# = u.obj#
and c.col# = u.intcol#
and o.owner# = r.user#

The execution plan will give you predicate information. For example,

SQL> select ename as name, job as junk
  2  from emp
  3  /

 select * from table( dbms_xplan.display_cursor( null, null, 'ADVANCED' ) )

Plan hash value: 3956160932

--------------------------------------------------------------------------
| Id  | Operation         | Name | Rows  | Bytes | Cost (%CPU)| Time     |
--------------------------------------------------------------------------
|   0 | SELECT STATEMENT  |      |       |       |     2 (100)|          |
|   1 |  TABLE ACCESS FULL| EMP  |    14 |   196 |     2   (0)| 00:00:01 |
--------------------------------------------------------------------------

Query Block Name / Object Alias (identified by operation id):
-------------------------------------------------------------

   1 - SEL$1 / EMP@SEL$1

Outline Data
-------------

  /*+
      BEGIN_OUTLINE_DATA
      IGNORE_OPTIM_EMBEDDED_HINTS
      OPTIMIZER_FEATURES_ENABLE('12.1.0.2')
      DB_VERSION('12.1.0.2')
      ALL_ROWS
      OUTLINE_LEAF(@"SEL$1")
      FULL(@"SEL$1" "EMP"@"SEL$1")
      END_OUTLINE_DATA
  */

Column Projection Information (identified by operation id):
-----------------------------------------------------------

   1 - "ENAME"[VARCHAR2,10], "JOB"[VARCHAR2,9]