How To Check If a Patch Is Applied in Oracle E Business Suite 11i, R12.1.X And R12.2.X

In Oracle EBS R12.2.x :

In Oracle E Business Suite  R12.2.x you cannot query the AD_BUGS table to check if patches have been applied..
The AD_BUGS table may have entries for patches that were applied but later the patching cycle was aborted (not really applied).
The way to check whether a patch is really applied is to use the AD_PATCH.IS_PATCH_APPLIED PL/SQL function.

Usage:
select AD_PATCH.IS_PATCH_APPLIED(\’$release\’,\’$appltop_id\’,\’$patch_no\’,\’$language\’)from dual;

or for single app tier installations:

example:-

select ad_patch.is_patch_applied (‘R12’, -1,20034256) from dual;

expected results:
EXPLICIT = applied
NOT APPLIED = not applied / aborted

Note: If you are sure patch is applied, but showing as not applied then do the following workaround

1. 1. Start admin from sourcing RUS FS
   2. Select Maintain Application File Menu
   3. Select 4. Maintain snapshot information
   4. Select 2. Update current view snapshot
   5. Select 1. update complete APPL_TOP

EBS 11i and R12.1 use below queries to check weather patch applied or not.
Select * from ad_bugs where bug_number=’bug_number’;
Select * from ad_applied_patches where patch_name=’bug_number’;
select A.APPLIED_PATCH_ID, A.PATCH_NAME, A.PATCH_TYPE, B.DRIVER_FILE_NAME, B.ORIG_PATCH_NAME,
B.CREATION_DATE, B.PLATFORM, B.SOURCE_CODE, B.CREATION_DATE, B.FILE_SIZE, B.MERGED_DRIVER_FLAG, B.MERGE_DATE from AD_APPLIED_PATCHES A, AD_PATCH_DRIVERS B where A.APPLIED_PATCH_ID = B.APPLIED_PATCH_ID and A.PATCH_NAME = ‘<patch number>’ ;