How does one write a DELETE CASCADE for postgres?

Question

I'm manually constructing a DELETE CASCADE statement for postgres.

I have a 'transaction' and a 'slice' table, related as shown below:

    Table "public.slice"   Column  | Type | Modifiers  ----------+------+-----------  id       | text | not null  name     | text |  Referenced by:     TABLE "transaction" CONSTRAINT "transaction_slice_id_fkey" FOREIGN KEY (slice_id) REFERENCES slice(id)  Table "public.transaction"   Column  | Type | Modifiers  ----------+------+-----------  id       | text | not null  slice_id | text |  Referenced by:     TABLE "classification_item" CONSTRAINT "classification_item_transaction_id_fkey" FOREIGN KEY (transaction_id) REFERENCES transaction(id) Table "public.classification_item"      Column     | Type | Modifiers  ----------------+------+-----------  id             | text | not null  transaction_id | text |  Foreign-key constraints:     "classification_item_transaction_id_fkey" FOREIGN KEY (transaction_id) REFERENCES transaction(id) 

Say I want to delete all transactions and classification_items referenced by the slice whose name is 'my_slice'. What do I need to write?

=# delete from classification_item where transaction_id= #...?  =# delete from transaction where slice_id= #...?  =# delete from slice where name='my_slice'; 

Answer 1

Postgres foreign keys support the CASCADE deletes:

slice_id integer REFERENCES slice(id) ON DELETE CASCADE 

etc