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DELETE all where MySQL foreign key constraint does not fail

开发者 https://www.devze.com 2023-03-26 07:52 出处:网络
I am trying to delete a few records but am getting the following error: Cannot delete or update a parent row: a foreign key constraint fails

I am trying to delete a few records but am getting the following error:

Cannot delete or update a parent row: a foreign key constraint fails

The thing is, the foreign key constraint is failing for only 1 or 2 of my 100 records I wish to delete. I wish to write a query which deletes these 98-99 records, skipping the 1 or 2 which failed, which I can later manually inspect and delete/modify. Not stopping because of some single problematic record, but continuing with the others, ignoring that.

Is there a neat way to d开发者_Python百科o this ?


You have to LEFT JOIN the referencing table and add a condition saying that the row is missing in that table.

For example:

DELETE a FROM a
LEFT JOIN b ON b.a_id = a.id
WHERE b.a_id IS NULL;


Use ignore:

DELETE IGNORE ...

http://dev.mysql.com/doc/refman/5.0/en/delete.html

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