How can I find the underlying column and table name for an Oracle view?

Question

This sounds like it should be simple to do but not so! There is no Oracle (meta-data) view that I can find that gives the underlying column and table name for an Oracle view col

Answer 1

The sql that defined the view can be found in all_views

set long 9999 
select TEXT from all_views where VIEW_NAME='MYVIEW';

This is the only way to get at the underlying tables and columns.

Answer 2

There isn't a way, because the definition of each view column is an expression, not (in general) merely a table column. For example, your view's SQL could be:

SELECT 
   UPPER(ENAME) || 'xxx',
   myfunction(DNAME)
FROM
   emp a,
   dept b
WHERE
   a.deptno= b.deptno

or perhaps

SELECT ename || 'xxx', dname
FROM (
  SELECT 
     UPPER(ENAME) AS ename,
     myfunction(DNAME) AS dname
  FROM
     emp a,
     dept b
  WHERE
     a.deptno= b.deptno
)

What would you expect to see for the "underlying columns" in this example?

Answer 3

In 11g Oracle introduced finer grained dependency tracking. So the database knows which table columns a view or package body depends on. However, they don't seem to have exposed this data in a view. But there may be x$ tables with the info.

Answer 4

The linked procedures may be of some help for identifying dependencies

The DBA_DEPENDENCIES View will give you a list of the tables that a View is based on:

SELECT *
  FROM DBA_DEPENDENCIES
 WHERE OWNER = <Schema>
   AND NAME = <View_Name>
   AND TYPE = 'VIEW'

Answer 5

Tables used to created the view can be selected using the query:

select 
  name , 
  type , 
  referenced_name , 
  referenced_type
from 
  user_dependencies 
where 
  name = 'VIEW_NAME' and 
  type = 'VIEW' and  
  referenced_type = 'TABLE';

If view columns have the same column name of table column, then please try the below query:

select 
  distinct table_name, column_name 
from 
  all_tab_columns 
where table_name in (select
                        referenced_name
                      from 
                        user_dependencies 
                      where 
                        name = 'VIEW_NAME' and 
                        type = 'VIEW' and  
                        referenced_type = 'TABLE') 
 and column_name in (select 
                        column_name 
                     from 
                        all_tab_columns 
                     where 
                        table_name = 'VIEW_NAME');

Answer 6

This works well if you want a views table and column dependencies:

WITH view_dependencies (view_name, table_name) AS (
    SELECT CONNECT_BY_ROOT d.name AS view_name, d.referenced_name AS table_name
    FROM all_dependencies d
    WHERE d.referenced_type IN ('TABLE', 'VIEW')
    START WITH d.name = UPPER('jtf_rs_resource_extns_vl') AND d.type = 'VIEW'
    CONNECT BY PRIOR d.referenced_name = d.name AND PRIOR d.referenced_type = d.type
)
SELECT deps.view_name, deps.table_name, tbl.table_id, cols.column_id, 
       cols.column_name  
FROM view_dependencies deps
    LEFT JOIN FND_TABLES tbl ON tbl.table_name = deps.table_name
    LEFT JOIN FND_COLUMNS cols ON tbl.table_id = cols.table_id
ORDER BY deps.view_name,  deps.table_name, cols.column_sequence;

Outputs

VIEW_NAME                   TABLE_NAME            TABLE_ID COLUMN_ID COLUMN_NAME
=======================================================================================
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563724  RESOURCE_ID
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563712  CREATED_BY
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563713  CREATION_DATE
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563718  LAST_UPDATED_BY
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563719  LAST_UPDATE_DATE
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563720  LAST_UPDATE_LOGIN
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563704  CATEGORY
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563725  RESOURCE_NUMBER
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563729  SOURCE_ID
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563686  ADDRESS_ID
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563709  CONTACT_ID
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563721  MANAGING_EMPLOYEE_ID
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563730  START_DATE_ACTIVE
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563714  END_DATE_ACTIVE
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563732  TIME_ZONE
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563711  COST_PER_HR
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563723  PRIMARY_LANGUAGE
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563726  SECONDARY_LANGUAGE
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563717  IES_AGENT_LOGIN
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563728  SERVER_GROUP_ID
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563687  ASSIGNED_TO_GROUP_ID
JTF_RS_RESOURCE_EXTNS_VL    JTF_RS_RESOURCE_EXTNS   80056   563710  COST_CENTER