CASCADE DELETE per statement

Question

Can I execute something like this in Postgresql, that is, execute CASCADE DELETE for just one statement?

DELETE CASCADE FROM foo WHERE bar = 'baz';

My goal is to delete not just the selected record(s) from table foo, but all the records in all the tables where foo.id column is used as a foreign key, without adding the constraint for the entire table foo: ON DELETE CASCADE.

Related:

• postgresql - CASCADE DELETE just once - Stack Overflow - a similar question was asked in 2008. I wonder if anything has changed since then.
• Deleting a row in one table should also delete the corresponding rows in another table - I want to avoid this, since it ALTERs the entire table, and affects all the DELETE statements. I want to do something like this, but on a per statement basis.
• PostgreSQL: Documentation: 16: 5.4. Constraints - could not find an answer in the docs.
• Is it a good or bad idea to use "ON UPDATE CASCADE ON DELETE CASCADE" for foreign keys? Why does this mechanism exist at all? - The pros and cons of ON DELETE CASCADE are discussed in the answers in this Q&A.

Answer 1

There is no way to automatically delete all dependent rows; you will have to delete them before you delete the referenced row.

Answer 2

1. ALTER and UPDATE each child table to have a copy of the field bar from its parent record in foo.
2. DELETE all rows in each child table where bar = 'baz'.
3. Clean up by ALTER DROP COLUMN on the new fields which are no longer needed.
4. Finally, DELETE the parent table's rows where bar = 'baz'.