Foreign Key Constraint Failure on Self-Referencing Table

Question

In a recent data deletion project, I ran into a problem where Oracle allowed for a record (the parent) to be deleted when there still existed a child record in the same table which referred to the parent.
An abbreviated version of the table is as follows:
create table test (
template_id number not null,
customer_id number null,
parent_id number null,
constraint pk_test primary key (template_id),
constraint r_parent foreign key (parent_id) references test (template_id));
The parent and child records are as follows:
Parent: template_id = 100, customer_id = 200, parent_id = null
Child: template_id = 101, customer_id = null, parent_id = 100
Records were deleted from this table using:
DELETE FROM test WHERE customer_id = 200;
When this statement is executed, is it being executed as part of 155 delete statements using PL/SQL, and tens of thousands of records from 155 tables are being deleted. These delete statements have been ordered taking into account foreign key constraints. All 155 statements are being deleted in a single transaction. The delete statement above was the 23rd statement of the set to be executed. I would have expected when this delete statement was executed, an error would have been thrown. However, all 155 delete statements successfully complete, and after committing the results, the child record above still exists in the DB as an orphan. I also tried executing the first 23 statements manually in SQL*Plus (still one transaction), and the problem still occurs: the parent is deleted and the child is orphaned.
If I execute the very simple example above, I do indeed get an referential constraint error.
Has anyone ever encountered this situation? And does anyone have any ideas how to go about troubleshooting this problem. We need to know the cause of this, as we have a small handful of table with a similar self-referential foreign key constraint set-up.
Thank you very much in advance,
Mark

Answer 1

First of all, the very simple example that I outlined above I have already tried and it worked: when I attempted to delete the parent a referential integrity error was thrown as one would expect. This small example was my test case to see if I could reproduce what I'm seeing in our application in a more manageable and demonstrable example. But as it worked, I'm still perplexed in reconciling the differences between what I'm seeing in our application (which I can't demonstrate in this help group) and the test case. When I used the test case in my first posting in this thread, I used it to help describe the problem I'm encountered, even though that small example works.
Below is more of the table you've asked for.
OWNER           CONSTRAINT_NAME          CONSTRAINT_TYPE     TABLE_NAME     SEARCH_CONDITION     R_OWNER            R_CONSTRAINT_NAME     DELETE_RULE     STATUS          DEFERRABLE            DEFERRED         VALIDATED     GENERATED     BAD     RELY     LAST_CHANGE           INDEX_OWNER  INDEX_NAME       INVALID     VIEW_RELATED
"DOCPADMIN"     "R_TEMPLATE_PARENT"     "R"             "DCR_TEMPLATE"      (null)                  "DOCPADMIN"     "XPKDCR_TEMPLATE"     "NO ACTION"  "ENABLED"   "NOT DEFERRABLE"    "IMMEDIATE"  "VALIDATED"      "USER NAME"     (null)     (null)     "2010-01-13 19:01:21"     (null)        (null)         (null)       (null)
"DOCPADMIN"     "XPKDCR_TEMPLATE"       "P"             "DCR_TEMPLATE"      (null)                       (null)     (null)                      (null)          "ENABLED"     "NOT DEFERRABLE"    "IMMEDIATE"      "VALIDATED"     "USER NAME"     (null)     (null)     "2010-01-13 15:48:31"     (null)     "XPKDCR_TEMPLATE"   (null)     (null)Overall, I haven't said that Oracle's FK mechanism is broken. What I've said is that I've got a situation that I'm trying to understand. My first attempt at my test case didn't work because the test case worked as it should. I'm trying to figure out another course of action to try and figure this situation out.