On 19 Jul 2022, at 5:10, Igor Korot wrote:
Hi, guys,
In the database theory each table is identified as "schema_name"."table_name".
When I tried to look at how to get the table id inside the PostgreSQL,
I saw that I needed to look at the pg_class table.
SELECT oid FROM pg_class WHERE relname = "table_name";
However that query will give a non-unique table id (see the first sentence).
So how do I get the table id based on the "schema_name.table_name"?
There is a pg_namespace table - is this where the schema should come from?
If yes - how?
Looking at that table I don't see any unique fields...
Or is this something that is hidden?
In fact I'm trying to run following query:
SELECT c.oid FROM pg_class c, pg_namespace nc WHERE nc.oid =
c.relnamespace AND c.relname = ? AND nc.nspname = ?;
from my ODBC based program, but it returns 0 rows on SQLFetch.
I know PostgreSQL does not use '?' for query parameters
but I thought that since its an ODBC everything should work.
Nevertheless, all bindings were successful, but now rows are returned.
Is this query correct?
Thank you.
That's more or less the same query that I am using:
select
r.oid as oid,
n.nspname || '.' || r.relname as name
from
pg_catalog.pg_namespace n
join
pg_catalog.pg_class r on n.oid = r.relnamespace
where
(r.relkind = 'r') and
(n.nspname not like 'pg_%') and
(n.nspname != 'information_schema') and
(n.nspname = 'email') and
(r.relname = 'emailhistory')
Maybe your problem has to to with uppercase/lowercase schema and/or table names?
Servus,
Walter
