oracle - integrity constraint violated - child record found - database

I have a huge pl/sql stored procedure, where we make some deletions as long as insertions.
Procedure starts with the statement
EXECUTE IMMEDIATE 'SET CONSTRAINTS ALL DEFERRED'
And at the last commit statement I receive ORA-02292: integrity constraint AAA violated.
The questions is that I don't know which statement exactly causes it, because I have both deletion from parent table (before child one) and insertions into child table before parent.
I tried to google it, but everywhere it's said that 02292 happens when I try to delete only.
Could this error happen when I try to insert value in the child table but there is no this entry in the parent?
Also, what is the difference between 02292 and 02291?

ORA-02292 indicates that the error occurred because A) the constraint has no ON DELETE clause specified, and B) you deleted a row from the master table which had matching references in the child table. Your choices are to modify the constraint so have an ON DELETE CASCADE or to ensure that all child records are deleted before deleting from the master. My preference would be to add ON DELETE CASCADE but I suppose there could be reasons not to do so. See ORA-02292.
ORA-02291 is sort of the opposite of this. ORA-02291 will be raised if you attempt to insert a row into a child table, but the key field values on your new child row as specified in the constraint do not exist in the master table. See ORA-02291.

If you want to disable the constraint from the name to solve ORA-02292.
Look for the table name bounded to that constraint
SELECT owner, table_name FROM dba_constraints WHERE constraint_name = '{CONSTRAINT_NAME}';
Disable constraint (this command should be executed by an admin user)
ALTER TABLE {TABLE_NAME} DISABLE constraint {CONSTRAINT_NAME} cascade;

Related

SQL Server, FK: Check in the (1) side NoCheck in the (Many) side

Suppose I have an ActiveCustomers table with some FKs (eg CountryID),
and I also have a NonActiveCustomers with the same FKs.
When I insert a new line to ActiveCustomers - the system must check the "1" side (from 1:N) to verify the CountryID (or whatever) exists.
When I move a line from ActiveCustomers to NonActiveCustomers - I don't need the system to verify it again because it has already been done when the line was originally inserted into ActiveCustomers.
In this case I can create a Check FK constraint on ActiveCustomers,
and a NoCheck FK constraint on NonActiveCustomers;
but the problem is that when I delete lines from the "1" side table (Countries), I want the system to check in both "N" tables that the operation is allowed: I don't want to have orphaned lines there.
How can I do that? The Nocheck disables all validations in the inserts to NonActiveCustomers and in the deletions & updates (in Countries), even when I specify explicitly On Delete No Action On Update No Action.
Of course, I can create a Trigger on Countries in order to verify that the Delete or Update are correct, but is there a way to do that using the constraint mechanism?

unable to truncate a parent table even after disabling a FK constraint in sql server

I am unable to truncate from a parent table by only disabling the FK constraint in the referring table . I had to actually drop the constraint in the referring table to be able to truncate the parent table.
I did the above step after first truncating the child table.....so I did follow the right order....do i really need to delete the constraint and then bulk insert the data and then re-create the FK constraint?
If you wanna use TRUNCATE then yes, dropping and recreating the constraint is the only way.
Confirmation in doc (with more explanations)
You cannot use TRUNCATE TABLE on a table referenced by a FOREIGN KEY
constraint; instead, use
DELETE statement without a WHERE clause. Because TRUNCATE TABLE is not
logged, it cannot activate a trigger.
If the child table is empty (or all of the relevant FK values are set to NULL), you should be able to DELETE from the parent table without disabling or dropping the constraint.
However you won't be able to use TRUNCATE even if you disable the constraint and even if the child table is empty. In this case SQL Server checks at the DDL level that the constraint exists and bails out long before it will ever bother checking the data for constraint violations (so it doesn't matter that the table is empty).
So, just use DELETE in your case. Unless you are doing this 50,000 times a day, trying to get this to work with TRUNCATE seems to be a lot of trouble for very little gain.

foreign key data deletion should display error for primary key

i have two tables Table1 and Table2. Where table1 column primary key is referred to table2 column as foreign key.
Now i have to display a error message of constraint violation when ever i delete records from table2 which is having foreign key column of table1.
If I get it right your column A (say) in table 1 references column B (say) in table 2.
What you can do is set the ON DELETE to NO ACTION which will prevent deletion of records from table 2 if any children of it still exists in table 1.
You can can do this by:
ALTER TABLE TABLE1 ADD FOREIGN KEY (A) REFERENCES TABLE2 (B) ON DELETE NO ACTION;
You don't have a constraint violation if you delete records from the child table and not the parent. It is normal to delete child records. For instance if I have a user table and a photos tables that contains the userid from the users table, why would I want to stop that action and throw an error if I want to delete a photo? Deleting a child record doesn't also delete the parent.
If you really want to do that, then you must do it through a trigger (make sure to handle multiple record deletes) or if the FK is a required field, then simply don't grant permissions to delete to the table. Be aware that this may mean you can never delete any records even when you try to delete. A simple method may be to not have a delete function available in the application.
I suspect what you really need to a to get a better definition of what is needed in the requirements document. In over 30 years of dealing with hundreds of databases, I have never seen anyone need this functionality.

Deleting a SQL row ignoring all foreign keys and constraints

I have a row in a table. This row has an ID column referenced in a few other tables with millions of rows. The SQL statement to delete the row always times out. From my design, I know the row I wish to delete is never referenced any where else. Hence I would like SQL to ignore having to check all other tables for a foreign key reference to this row and delete the row immediately. Is there a quick way to do this in SQL 2008?
Perhaps something along the lines of:
DELETE FROM myTable where myTable.ID = 6850 IGNORE CONSTRAINTS
Or something along those lines.
You can set the constraints on that table / column to not check temporarily, then re-enable the constraints. General form would be:
ALTER TABLE TableName NOCHECK CONSTRAINT ConstraintName
Then re-enable all constraints with
ALTER TABLE TableName CHECK CONSTRAINT ConstraintName
I assume that this would be temporary though? You obviously wouldn't want to do this consistently.
Yes, simply run
DELETE FROM myTable where myTable.ID = 6850
AND LET ENGINE VERIFY THE CONSTRAINTS.
If you're trying to be 'clever' and disable constraints, you'll pay a huge price: enabling back the constraints has to verify every row instead of the one you just deleted. There are internal flags SQL keeps to know that a constraint is 'trusted' or not. You're 'optimization' would result in either changing these flags to 'false' (meaning SQL no longer trusts the constraints) or it has to re-verify them from scratch.
See Guidelines for Disabling Indexes and Constraints and Non-trusted constraints and performance.
Unless you did some solid measurements that demonstrated that the constraint verification of the DELETE operation are a performance bottleneck, let the engine do its work.
Do not under any circumstances disable the constraints. This is an extremely stupid practice. You cannot maintain data integrity if you do things like this. Data integrity is the first consideration of a database because without it, you have nothing.
The correct method is to delete from the child tables before trying to delete the parent record. You are probably timing out because you have set up cascading deltes which is another bad practice in a large database.
I know this is an old thread, but I landed here when my row deletes were blocked by foreign key constraints. In my case, my table design permitted "NULL" values in the constrained column. In the rows to be deleted, I changed the constrained column value to "NULL" (which does not violate the Foreign Key Constraint) and then deleted all the rows.
I wanted to delete all records from both tables because it was all test data. I used SSMS GUI to temporarily disable a FK constraint, then I ran a DELETE query on both tables, and finally I re-enabled the FK constraint.
To disable the FK constraint:
expand the database object [1]
expand the dependant table object [2]
expand the 'Keys' folder
right click on the foreign key
choose the 'Modify' option
change the 'Enforce Foreign Key Constraint' option to 'No'
close the 'Foreign Key Relationships' window
close the table designer tab
when prompted confirm save changes
run necessary delete queries
re-enable foreign key constraint the same way you just disabled it.
[1] in the 'Object Explorer' pane, can be accessed via the 'View' menu option, or key F8
[2] if you're not sure which table is the dependant one, you can check by right clicking the table in question and selecting the 'View Dependencies' option.
This is the way to disable foreign key checks in MySQL. Not relevant to OP's question since they use MS SQL Server, but google search results do turn this up so here's for reference:
SET FOREIGN_KEY_CHECKS = 0;
/ Run your script /
SET FOREIGN_KEY_CHECKS = 1;
See if this helps, This is for ignoring the foreign key checks.
But deleting disabling this is very bad practice.
On all tables with foreign keys pointing to this one, use:
ALTER TABLE MyOtherTable NOCHECK CONSTRAINT fk_name
You can disable all of the constaints on your database by the following line of code:
EXEC sp_MSforeachtable "ALTER TABLE ? NOCHECK CONSTRAINT all"
and after the runing your update/delete command, you can enable it again as the following:
EXEC sp_MSforeachtable "ALTER TABLE ? WITH CHECK CHECK CONSTRAINT all"
You could maybe disable and re-enable constraints:
http://sqlforums.windowsitpro.com/web/forum/messageview.aspx?catid=60&threadid=48410&enterthread=y
For the testing purpose only, I used the following command in MySQL to delete only one record from a table that has foreign key references.
SET FOREIGN_KEY_CHECKS = 0; -- Disabling foreign key checks before running the following query.
DELETE FROM table_name WHERE id = id_to_delete; -- Deleting a record from a table that has foreign key reference.
SET FOREIGN_KEY_CHECKS = 1; -- Enabling foreign key checks after running the above query.
Temporarily disable constraints on a table T-SQL, SQL Server
MSSQL
ALTER TABLE TableName NOCHECK CONSTRAINT ALL
ALTER TABLE TableName CHECK CONSTRAINT ALL
ALTER TABLE TableName NOCHECK CONSTRAINT FK_Table_RefTable
ALTER TABLE TableName CHECK CONSTRAINT FK_Table_RefTable
ref
DELETE FROM TableName
DBCC CHECKIDENT ('TableName', RESEED, 0)
MySql
SET FOREIGN_KEY_CHECKS = 0; -- Disable foreign key checking.
TRUNCATE TABLE [YOUR TABLE];
SET FOREIGN_KEY_CHECKS = 1;

SQL Server update primary key that's also a foreign key in two tables

I need to update the primary key for a record but it's also the foreign key in two other tables. And I need the updated primary key to be reflected in the child tables as well.
Here is my query and the error:
begin tran
update question set questionparent = 10000, questionid= 10005 where questionid = 11000;
Error 9/4/2009 10:04:49 AM 0:00:00.000 SQL Server Database Error: The UPDATE statement conflicted with the REFERENCE constraint "FK_GoalRequirement_Question". The conflict occurred in database "numgmttest", table "dbo.GoalRequirement", column 'QuestionID'. 14 0
I don't remember how to go about doing this so that's why I'm here. Any help?
Are your relationships using
ON UPDATE CASCADE
If they are then changing the key in the primary table will update the foreign keys.
e.g.
ALTER TABLE Books
ADD CONSTRAINT fk_author
FOREIGN KEY (AuthorID)
REFERENCES Authors (AuthorID) ON UPDATE CASCADE
You may:
disable enforcing FK constraints temporarily (see here or here)
update your PK
update your FKs
enable back enforcing FK constraints
do it all within a transaction and make sure that if transaction fails, you roll it back properly and still enforce the FK constraints back.
But... why do you need to change a PK? I hope this is an action that is executed rarely (legacy data import or something like that).
If you would like to set the Cascade rule graphically then Set Cascade Rule on SQL Management Studio
Open table in design mode
Click Relationship button from top toolbar
Select the required FK relations (one by one)
Right Side - Expand INSERT or UPDATE Specification
Change the UPDATE Rule to - Cascade
Close and Save, Done!
(Tried on SQL 2008)
As I'm not too confident disabling FK constraints, I prefer too :
Duplicate the row with the old PK with one with the new PK
Update the FKs
Delete the row with the old PK
Advantage : No constraint violated during the process.
Go to foreign Key Relations of each child tables and on Insert and Update specification change delete and update rules to cascade.
create a New row with the same data and a different primary key.
update all the children tables.
remove the row that you repeated its data
And its done.

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