Don't repeat yourself: same SQL query, but two different tables

Question

I have an SQL query with exact the same code, but two different tables (AUDIT_TRAIL_ARCHIVE and AUDIT_TRAIL). I use "UNION ALL" to have one result.

Good programmers use "Don't repeat yourself" principle. Good programmers avoid WET (write everything twice).

Howto rewrite this code with "Don't repeat yourself" principle?

SELECT REPLACE (ENTITY_KEY, 'rss_user_name=CN=', '')
 FROM    AUDIT_TRAIL_ARCHIVE AU
   INNER JOIN
      (SELECT RSS_USER_NAME
         FROM RSS_USER
        WHERE RSS_NAME = 'rmad'
              AND ADD_INFO_MASTER LIKE '%__47__UPN=%@richemont.com%') FALSCH
   ON REPLACE (AU.ENTITY_KEY, 'rss_user_name=CN=', '') =
         FALSCH.RSS_USER_NAME
WHERE     AU.RSS_NAME = 'rmad'
   AND AU.TABLE_NAME = 'rss_user'
   AND AU.ACTION = 'Insert'
   AND AU.ENTITY_KEY LIKE 'rss_user_name=CN=%'
   AND AU.ORIGIN != 'RSS'
UNION ALL
SELECT REPLACE (ENTITY_KEY, 'rss_user_name=CN=', '')
 FROM    AUDIT_TRAIL AU
   INNER JOIN
      (SELECT RSS_USER_NAME
         FROM RSS_USER
        WHERE RSS_NAME = 'rmad'
              AND ADD_INFO_MASTER LIKE '%__47__UPN=%@richemont.com%') FALSCH
   ON REPLACE (AU.ENTITY_KEY, 'rss_user_name=CN=', '') =
         FALSCH.RSS_USER_NAME
WHERE     AU.RSS_NAME = 'rmad'
   AND AU.TABLE_NAME = 'rss_user'
   AND AU.ACTION = 'Insert'
   AND AU.ENTITY_KEY LIKE 'rss_user_name=CN=%'
   AND AU.ORIGIN != 'RSS'

Answer 1

For example:

SELECT REPLACE (ENTITY_KEY, 'rss_user_name=CN=', '')
 FROM    (select * --or relevant columns
          from AUDIT_TRAIL_ARCHIVE AU
          union all
          select * 
          from AUDIT_TRAIL AU
           ) AU
   INNER JOIN
      (SELECT RSS_USER_NAME
         FROM RSS_USER
        WHERE RSS_NAME = 'rmad'
              AND ADD_INFO_MASTER LIKE '%__47__UPN=%@richemont.com%') FALSCH
   ON REPLACE (AU.ENTITY_KEY, 'rss_user_name=CN=', '') =
         FALSCH.RSS_USER_NAME
WHERE     AU.RSS_NAME = 'rmad'
   AND AU.TABLE_NAME = 'rss_user'
   AND AU.ACTION = 'Insert'
   AND AU.ENTITY_KEY LIKE 'rss_user_name=CN=%'
   AND AU.ORIGIN != 'RSS'