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Oracle Procedures to delete the parent child table rows with integrity constraints.

With some very hard work and innovative thinking we came up with the procedures (can be easily clubbed into package) to delete the parent child relationship row with any number of levels.

Below code would find the child row of the parent row being deleted and delete it first , if the child row has its own child then that childs children are fetched and deleted so its basically a recursive algorithm

There are not many situations where you would want to use this. We had a customer mstr record to be deleted which had 20 levels of child records held tight by (ORA-02292: integrity constraint   violated - child record found ) with their parent child constraints.

Since this only was a delete for 1 Master record we went ahead and used this script. If you have more than 20 levels Wise course would be to disable constraints and really think why you want to delete such master record.

Note of caution : BE CAREFUL using this on production environment.

The procedures create the insert statements along the line as it deletes the parent child rows  , but  its done in DBMS_OUTPUT so make sure you have that turned on if you want insert statement roll back plan to be created.  You can of course be innovative and dump inserts in another table or use utl_file to write them elsewhere.

Usage : Find DEL_PARENT_CHILD On
2nd Last line is the call to main recursive delete.
1st Argument is TABLE NAME here (Order_Header_TBL)
2nd Argument is Where Clause  PROCEDURE CAN DELETE ONLY 1 PARENT LINE AT A TIME.
MAKE SURE YOUR WHERE CLAUSE IS FETCHING ONLY 1 ROW.
If you want to delete multiple rows call it that many times in a lopp or whichever way you see fit.

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