Re: Postgres C-API: How to get the Oid for a custom type defined in a schema outside of the current search path
| От | Pavel Stehule |
|---|---|
| Тема | Re: Postgres C-API: How to get the Oid for a custom type defined in a schema outside of the current search path |
| Дата | |
| Msg-id | CAFj8pRDH0g2JT9g457PVi7+wd=-YqktzWBcvKeen6cu5m5VQwQ@mail.gmail.com обсуждение исходный текст |
| Ответ на | Postgres C-API: How to get the Oid for a custom type defined in a schema outside of the current search path (Michael Krüger <michael@kruegers.email>) |
| Ответы |
Re: Postgres C-API: How to get the Oid for a custom type defined in a schema outside of the current search path
|
| Список | pgsql-general |
Hi
čt 3. 12. 2020 v 10:32 odesílatel Michael Krüger <michael@kruegers.email> napsal:
Dear all,I need to find out the Oid of a custom type in C programming language. This type is defined in a schema, outside of the standard search path, e.g. public.I know that I can call TypenameGetTypid to find out an Oid. But this is not working for me if the type is not in the public namespace.
How can I query a non-public Oid? Do I have to change the search path? If yes how do I do it? As mentioned I need to do this with the C interface.
I looking to source code
Oid
TypenameGetTypidExtended(const char *typname, bool temp_ok)
{
<-->Oid><--><-->typid;
<-->ListCell *l;
<-->recomputeNamespacePath();
<-->foreach(l, activeSearchPath)
<-->{
<--><-->Oid><--><-->namespaceId = lfirst_oid(l);
<--><-->if (!temp_ok && namespaceId == myTempNamespace)
<--><--><-->continue;<-><--><-->/* do not look in temp namespace */
<--><-->typid = GetSysCacheOid2(TYPENAMENSP, Anum_pg_type_oid,
<--><--><--><--><--><--><--><-->PointerGetDatum(typname),
<--><--><--><--><--><--><--><-->ObjectIdGetDatum(namespaceId));
<--><-->if (OidIsValid(typid))
<--><--><-->return typid;
<-->}
<-->/* Not found in path */
<-->return InvalidOid;
}
TypenameGetTypidExtended(const char *typname, bool temp_ok)
{
<-->Oid><--><-->typid;
<-->ListCell *l;
<-->recomputeNamespacePath();
<-->foreach(l, activeSearchPath)
<-->{
<--><-->Oid><--><-->namespaceId = lfirst_oid(l);
<--><-->if (!temp_ok && namespaceId == myTempNamespace)
<--><--><-->continue;<-><--><-->/* do not look in temp namespace */
<--><-->typid = GetSysCacheOid2(TYPENAMENSP, Anum_pg_type_oid,
<--><--><--><--><--><--><--><-->PointerGetDatum(typname),
<--><--><--><--><--><--><--><-->ObjectIdGetDatum(namespaceId));
<--><-->if (OidIsValid(typid))
<--><--><-->return typid;
<-->}
<-->/* Not found in path */
<-->return InvalidOid;
}
You can get the value from sys cache by call GetSysCacheOid2. It can looks like
<--><-->char<--> *schemaname;
<--><-->char<--> *typname;
<--><-->char<--> *typname;
<--><--><-->namespaceId = LookupExplicitNamespace(schemaname, missing_ok);
<--><--><-->if (OidIsValid(namespaceId))
<--><--><--><-->typoid = GetSysCacheOid2(TYPENAMENSP, Anum_pg_type_oid,
<--><--><--><--><--><--><--><--><--><--> PointerGetDatum(typname),
<--><--><--><--><--><--><--><--><--><--> ObjectIdGetDatum(namespaceId));
<--><--><-->else
<--><--><--><-->typoid = InvalidOid;
<--><--><-->if (OidIsValid(namespaceId))
<--><--><--><-->typoid = GetSysCacheOid2(TYPENAMENSP, Anum_pg_type_oid,
<--><--><--><--><--><--><--><--><--><--> PointerGetDatum(typname),
<--><--><--><--><--><--><--><--><--><--> ObjectIdGetDatum(namespaceId));
<--><--><-->else
<--><--><--><-->typoid = InvalidOid;
Regards
Pavel
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