Solved

Oracle delete from tables with referential integrity

Posted on 2016-07-25
5
94 Views
Last Modified: 2016-08-16
Experts,
I have 3 tables say a, b and c. table a has the primary key 'a_id' and table b has the primary key 'b_id' and also foreign key from table a as 'a_id'. Table c has the primary key 'c_id' and the foreign key from table b which is 'b_id'.
If I want to delete a record from table a which has child record in table b and the child record in table b has a child record in table c.

can it be done in a single delete statement?
0
Comment
Question by:smalig
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
5 Comments
 
LVL 32

Expert Comment

by:awking00
ID: 41728285
If you disable the foreign keys for tables b and c and table a was created with on delete cascade. You should be able to delete the record from table a. However, you would need to delete the child records from b and c before you could re-enable the foreign keys.
0
 
LVL 77

Accepted Solution

by:
slightwv (䄆 Netminder) earned 500 total points
ID: 41728290
If you set the constraints to cascade on delete, then a single delete will remove all the children as well.
0
 
LVL 32

Expert Comment

by:awking00
ID: 41728291
I meant to say if the delete rule for b and c is not cascade, you would need to remove the child records first before re-enabling.
0
 
LVL 143

Expert Comment

by:Guy Hengel [angelIII / a3]
ID: 41728292
in other terms: with the referential constraints ( foreign key ) enabled, you delete from table a only

ogherwise you delete from c first, then from b, finally from a
0
 
LVL 32

Expert Comment

by:awking00
ID: 41728295
slightwv is right. I should have stopped my initial response after the second sentence.
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
setting local variables in a cursor block 3 44
Need help on decision table structure 7 58
construct a query sql 11 43
Oracle SQL-Queries on a RAC Database 3 48
How to Create User-Defined Aggregates in Oracle Before we begin creating these things, what are user-defined aggregates?  They are a feature introduced in Oracle 9i that allows a developer to create his or her own functions like "SUM", "AVG", and…
When it comes to protecting Oracle Database servers and systems, there are a ton of myths out there. Here are the most common.
This video explains at a high level with the mandatory Oracle Memory processes are as well as touching on some of the more common optional ones.
This video shows syntax for various backup options while discussing how the different basic backup types work.  It explains how to take full backups, incremental level 0 backups, incremental level 1 backups in both differential and cumulative mode a…

710 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question