Re: Res: Finding all tables that have foreign keys referencing a table

On Friday 07 November 2008 15:15:49 paulo matadr wrote:
> Try this
>
> select table_schema, table_name
> from information_schema.columns
> where table_schema not in
> ('information_schema','pg_catalog')
> and column_name = '?'

AFAICS this lists all tables which have a column named '?', which is not what I'm after. I'm after listing all columns referencing a certain column as a FOREIGN KEY.

Example, making the FK's names "$1" to mimic old PG-behaviour, and proving my point about the FK-names not needing to be globaly unique:

CREATE TABLE test1(
id INTEGER PRIMARY KEY
);

CREATE TABLE test2(
id INTEGER PRIMARY KEY
);

CREATE TABLE test_ref1(
id INTEGER PRIMARY KEY,
entity_id INTEGER,
CONSTRAINT "$1" FOREIGN KEY (entity_id) REFERENCES test1(id)
);

CREATE TABLE test_ref2(
id INTEGER PRIMARY KEY,
entity_id INTEGER,
CONSTRAINT "$1" FOREIGN KEY (entity_id) REFERENCES test2(id)
);

andreak=# \d test_ref1
Table "public.test_ref1"
Column | Type | Modifiers
-----------+---------+-----------
id | integer | not null
entity_id | integer |
Indexes:
"test_ref1_pkey" PRIMARY KEY, btree (id)
Foreign-key constraints:
"$1" FOREIGN KEY (entity_id) REFERENCES test1(id)

andreak=# \d test_ref2
Table "public.test_ref2"
Column | Type | Modifiers
-----------+---------+-----------
id | integer | not null
entity_id | integer |
Indexes:
"test_ref2_pkey" PRIMARY KEY, btree (id)
Foreign-key constraints:
"$1" FOREIGN KEY (entity_id) REFERENCES test2(id)

andreak=#

Now, any idea about how to safely get all columns which reference test1.id?
-hackers; Any hints?

BTW:
andreak=# select version();
version
-----------------------------------------------------------------------------------------------
PostgreSQL 8.3.3 on i486-pc-linux-gnu, compiled by GCC cc (GCC) 4.2.3 (Ubuntu 4.2.3-2ubuntu7)

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Andreas Joseph Krogh <andreak(at)officenet(dot)no>
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