On 2024-05-18 03:27 +0200, David G. Johnston wrote:
> > On 2024-05-16 17:47 +0200, David G. Johnston wrote:
> > > We have a glossary.
>
> If sticking with stand-alone composite type as a formal term we should
> document it in the glossary. It's unclear whether this will survive review
> though. With the wording provided in this patch it doesn't really add
> enough to continue a strong defense of it.
Oh, I thought you meant we already have that term in the glossary (I
haven't checked until now). Let's see if we can convince Robert of the
rewording.
> > It's now a separate error message (like I already had in v1) which
> > states that the specified type must not be a row type of another table
> > (based on Peter's feedback). And the hint directs the user to CREATE
> > TYPE.
> >
> > In passing, I also quoted the type name in the existing error message
> > for consistency. I saw that table names etc. are already quoted in
> > other error messages.
> >
> >
> The hint and the quoting both violate the documented rules for these things:
>
> https://www.postgresql.org/docs/current/error-style-guide.html#ERROR-STYLE-GUIDE-QUOTES
>
> There are functions in the backend that will double-quote their own output
> as needed (for example, format_type_be()). Do not put additional quotes
> around the output of such functions.
>
> https://www.postgresql.org/docs/current/error-style-guide.html#ERROR-STYLE-GUIDE-GRAMMAR-PUNCTUATION
>
> Detail and hint messages: Use complete sentences, and end each with a
> period. Capitalize the first word of sentences.
Thanks, I didn't know that guideline. Both fixed in v6.
--
Erik
>From 39d2dc9b58dfa3b68245070648ecdf9eed892c7a Mon Sep 17 00:00:00 2001
From: Erik Wienhold <e...@ewie.name>
Date: Fri, 8 Mar 2024 04:21:56 +0100
Subject: [PATCH v6] Document that typed tables rely on CREATE TYPE
CREATE TABLE OF requires a stand-alone composite type that is not the
row type of another table. Clarify that with a reference to CREATE TYPE
in the docs. Also report a separate error message in this case.
Reworded docs provided by David G. Johnston.
---
doc/src/sgml/ref/create_table.sgml | 16 ++++++++--------
src/backend/commands/tablecmds.c | 9 ++++++++-
src/test/regress/expected/typed_table.out | 7 ++++++-
src/test/regress/sql/typed_table.sql | 4 ++++
4 files changed, 26 insertions(+), 10 deletions(-)
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index f19306e776..11458be9cf 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -249,18 +249,18 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<listitem>
<para>
Creates a <firstterm>typed table</firstterm>, which takes its
- structure from the specified composite type (name optionally
- schema-qualified). A typed table is tied to its type; for
- example the table will be dropped if the type is dropped
- (with <literal>DROP TYPE ... CASCADE</literal>).
+ structure from an existing (name optionally schema-qualified) stand-alone
+ composite type (i.e., created using <xref linkend="sql-createtype"/>)
+ though it still produces a new composite type as well. The table will
+ have a dependency on the referenced type such that cascaded alter and
+ drop actions on the type will propagate to the table.
</para>
<para>
- When a typed table is created, then the data types of the
- columns are determined by the underlying composite type and are
- not specified by the <literal>CREATE TABLE</literal> command.
+ A typed table always has the same column names and data types as the
+ type it is derived from, and you cannot specify additional columns.
But the <literal>CREATE TABLE</literal> command can add defaults
- and constraints to the table and can specify storage parameters.
+ and constraints to the table, as well as specify storage parameters.
</para>
</listitem>
</varlistentry>
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 313c782cae..2331a9185a 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -6935,8 +6935,15 @@ check_of_type(HeapTuple typetuple)
* the type before the typed table creation/conversion commits.
*/
relation_close(typeRelation, NoLock);
+
+ if (!typeOk)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("type %s must not be a row type of another table",
+ format_type_be(typ->oid)),
+ errhint("Must be a stand-alone composite type created with CREATE TYPE.")));
}
- if (!typeOk)
+ else
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("type %s is not a composite type",
diff --git a/src/test/regress/expected/typed_table.out b/src/test/regress/expected/typed_table.out
index 2e47ecbcf5..5743e74978 100644
--- a/src/test/regress/expected/typed_table.out
+++ b/src/test/regress/expected/typed_table.out
@@ -89,8 +89,13 @@ drop cascades to function get_all_persons()
drop cascades to table persons2
drop cascades to table persons3
CREATE TABLE persons5 OF stuff; -- only CREATE TYPE AS types may be used
-ERROR: type stuff is not a composite type
+ERROR: type stuff must not be a row type of another table
+HINT: Must be a stand-alone composite type created with CREATE TYPE.
DROP TABLE stuff;
+CREATE TYPE simple AS ENUM ('a');
+CREATE TABLE of_simple OF simple; -- not a composite type
+ERROR: type simple is not a composite type
+DROP TYPE simple;
-- implicit casting
CREATE TYPE person_type AS (id int, name text);
CREATE TABLE persons OF person_type;
diff --git a/src/test/regress/sql/typed_table.sql b/src/test/regress/sql/typed_table.sql
index 9ef0cdfcc7..d9b9398857 100644
--- a/src/test/regress/sql/typed_table.sql
+++ b/src/test/regress/sql/typed_table.sql
@@ -50,6 +50,10 @@ CREATE TABLE persons5 OF stuff; -- only CREATE TYPE AS types may be used
DROP TABLE stuff;
+CREATE TYPE simple AS ENUM ('a');
+CREATE TABLE of_simple OF simple; -- not a composite type
+DROP TYPE simple;
+
-- implicit casting
--
2.45.1
