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

If you can convert your query into VIEW and then use INFORMATION_SCHEMA.VIEW_COLUMN_USAGE

Here is an example:

let's say your view name is ABC

then use this one

SELECT VIEW_NAME, TABLE_NAME, COLUMN_NAME  
FROM    INFORMATION_SCHEMA.VIEW_COLUMN_USAGE 
WHERE   VIEW_NAME = 'ABC'

Let me know if it works..

Answer 2

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]

Answer 3

I have a great solution for you, but there are two things you will need to do:

1. Place the SQL inside a PL/SQL program unit. So, yes, to the stored procedure you mentioned.

2. Compile that program unit and all dependent tables (that is, install your application code) on a 12.2 instance (you can download 12.2 at http://www.oracle.com/technetwork/database/enterprise-edition/downloads/index.html or you can purchase an Exadata Express CLoud Service at cloud.oracle.com or get a $300 credit to use one at no cost for a month at cloud.oracle.com/tryit).

12.2 is key because the feature you REALLY want to use is called PL/Scope and it is a compiler tool that collections information about PL/SQL identifiers (as of 11.1) and SQL usage inside PL/'SQL (as of 12.2).

CREATE TABLE my_data (n NUMBER)
/

ALTER SESSION SET plscope_settings='identifiers:all, statements:all'
/

CREATE OR REPLACE PROCEDURE my_procedure (n_in IN NUMBER)
   AUTHID DEFINER
IS
   l_n           my_data.n%TYPE;

   CURSOR all_data_cur
   IS
          SELECT *
            FROM my_data
      FOR UPDATE OF n;
BEGIN
   INSERT INTO my_data (n)
        VALUES (n_in);

END;
/

  SELECT idt.line,
         idt.owner || '.' || idt.object_name code_unit, 
         idt.name column_name,
         RTRIM (src.text, CHR (10)) text
    FROM all_identifiers idt, all_source src
   WHERE     idt.usage = 'REFERENCE'
         AND idt.TYPE = 'COLUMN'
         AND idt.line = src.line
         AND idt.object_name = src.name
         AND idt.owner = src.owner
         AND idt.object_name = 'MY_PROCEDURE'
ORDER BY code_unit, line
/

LINE CODE_UNIT          COLUMN_NAME TEXT  
4   STEVEN.MY_PROCEDURE N           l_n           my_data.n%TYPE;
10  STEVEN.MY_PROCEDURE N           FOR UPDATE OF n;
12  STEVEN.MY_PROCEDURE N           INSERT INTO my_data (n)

Hope that helps!

Lots more examples of PL/Scope at livesql.oracle.com. Just search for "pl/scope" (duh).