如何为postgres编写DELETE CASCADE？

想飞的火

我正在手动为postgres构造DELETE CASCADE语句。
. m1 K* Q1 S4 _8 _7 C" `5 \: b( y5 w我有一个“交易”和一个“切片”表，如下所示：
( I+ G$ g1 @% |# B    Table "public.slice"
* e$ G" Z& C# N4 s" M( E7 c9 n  Column  | Type | Modifiers
----------+------+-----------
id       | text | not null
name     | text |
; l3 E$ e; A) o+ s# YReferenced by:
6 p! F, N5 J4 g. f/ q% ?    TABLE "transaction" CONSTRAINT "transaction_slice_id_fkey" FOREIGN KEY (slice_id) REFERENCES slice(id)
Table "public.transaction"
; K5 w1 v$ [$ E7 a# r6 _$ H  Column  | Type | Modifiers
' X; S1 K- ]& G( j----------+------+-----------
id       | text | not null
slice_id | text |
Referenced by:
. ?6 H$ o9 A! I6 O9 F/ v    TABLE "classification_item" CONSTRAINT "classification_item_transaction_id_fkey" FOREIGN KEY (transaction_id) REFERENCES transaction(id)
Table "public.classification_item"
$ X8 o( M' P' j$ ]! I     Column     | Type | Modifiers
1 N. c" z0 X; l----------------+------+-----------
id             | text | not null
transaction_id | text |
Foreign-key constraints:
    "classification_item_transaction_id_fkey" FOREIGN KEY (transaction_id) REFERENCES transaction(id)
; S3 e: M" ~* X" \5 y9 f假设我要删除名称为“ my_slice”的切片所引用的所有事务和category_item。我需要写些什么？
=# delete from classification_item where transaction_id= #...?
# F0 u6 w: N' F( E" j0 g=# delete from transaction where slice_id= #...?
5 H% |, Q& m" a7 j: _* f=# delete from slice where name='my_slice';
$ J0 p" y; F2 s5 {, a" t7 P* A               
解决方案:
               

) h" d0 Q% J% {- e! V7 }
7 B) y" {( E1 O( j8 V' @  t                万一您不能做别人建议的事情：
begin;
" b4 _3 R; C3 Y. E" G; A" N# ndelete from classification_item where transaction_id in (select id from "transaction" where slice_id = (select id from slice where name = 'my_slice'));
delete from "transaction" where slice_id in (select id from slice where name='my_slice');
delete from slice where name='my_slice';
4 i: J. `0 A1 K' Y" x/ Tcommit;