Re: CREATE TABLE creates a composite type corresponding to the table row, which is and is not there - Mailing list pgsql-hackers
From | Tom Lane |
---|---|
Subject | Re: CREATE TABLE creates a composite type corresponding to the table row, which is and is not there |
Date | |
Msg-id | 1556597.1721939351@sss.pgh.pa.us Whole thread Raw |
In response to | Re: CREATE TABLE creates a composite type corresponding to the table row, which is and is not there (Erik Wienhold <ewie@ewie.name>) |
Responses |
Re: CREATE TABLE creates a composite type corresponding to the table row, which is and is not there
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List | pgsql-hackers |
Erik Wienhold <ewie@ewie.name> writes: > Thanks, I didn't know that guideline. Both fixed in v6. This still isn't following our usual message style IMO. Here's a proposed v7 that outputs -ERROR: type stuff is not a composite type +ERROR: type stuff is the row type of another table +DETAIL: A typed table must use a stand-alone composite type created with CREATE TYPE. I did a bit of copy-editing on the docs changes too. One notable point is that I dropped the parenthetical bit about "(name optionally schema-qualified)". That struck me as quite unnecessary, and it definitely doesn't read well to have two parenthetical comments in a single four-line sentence. regards, tom lane diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml index f19306e776..93b3f664f2 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 the specified stand-alone composite type (that is, + one 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, meaning that cascaded alter and + drop actions on that 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, so 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 721d24783b..0b2a52463f 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -6962,8 +6962,15 @@ 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 is the row type of another table", + format_type_be(typ->oid)), + errdetail("A typed table must use 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..b6fbda3f21 100644 --- a/src/test/regress/expected/typed_table.out +++ b/src/test/regress/expected/typed_table.out @@ -89,7 +89,12 @@ 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 is the row type of another table +DETAIL: A typed table must use a stand-alone composite type created with CREATE TYPE. +CREATE TYPE tt_enum_type AS ENUM ('a'); +CREATE TABLE of_tt_enum_type OF tt_enum_type; -- not a composite type at all +ERROR: type tt_enum_type is not a composite type +DROP TYPE tt_enum_type; DROP TABLE stuff; -- implicit casting CREATE TYPE person_type AS (id int, name text); diff --git a/src/test/regress/sql/typed_table.sql b/src/test/regress/sql/typed_table.sql index 9ef0cdfcc7..57ce12782b 100644 --- a/src/test/regress/sql/typed_table.sql +++ b/src/test/regress/sql/typed_table.sql @@ -48,6 +48,10 @@ DROP TYPE person_type CASCADE; CREATE TABLE persons5 OF stuff; -- only CREATE TYPE AS types may be used +CREATE TYPE tt_enum_type AS ENUM ('a'); +CREATE TABLE of_tt_enum_type OF tt_enum_type; -- not a composite type at all +DROP TYPE tt_enum_type; + DROP TABLE stuff;
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