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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2002-12-16 19:08:25 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2002-12-16 19:08:25 +0000 |
| commit | 9cecff0314c3c75248f29fea6b80c19d9a8a8c70 (patch) | |
| tree | e1f2bd0cb5cc9e438f0c0f783500d8862d3651ad | |
| parent | 5131e5ab7d75279fe78d025f6d6668f15d7efd67 (diff) | |
| download | postgresql-9cecff0314c3c75248f29fea6b80c19d9a8a8c70.tar.gz postgresql-9cecff0314c3c75248f29fea6b80c19d9a8a8c70.zip | |
Document that zero-column tables are allowed (and non-standard).
| -rw-r--r-- | doc/src/sgml/ref/alter_table.sgml | 8 | ||||
| -rw-r--r-- | doc/src/sgml/ref/create_table.sgml | 15 |
2 files changed, 21 insertions, 2 deletions
diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml index 8c4d6980fed..a8cbfb5bc68 100644 --- a/doc/src/sgml/ref/alter_table.sgml +++ b/doc/src/sgml/ref/alter_table.sgml @@ -1,5 +1,5 @@ <!-- -$Header: /cvsroot/pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.52 2002/10/19 23:09:20 tgl Exp $ +$Header: /cvsroot/pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.53 2002/12/16 19:08:25 tgl Exp $ PostgreSQL documentation --> @@ -506,6 +506,12 @@ ALTER TABLE distributors ADD PRIMARY KEY (dist_id); The clauses to rename tables, columns, indexes, and sequences are <productname>PostgreSQL</productname> extensions from SQL92. </para> + + <para> + <command>ALTER TABLE DROP COLUMN</> can be used to drop the only column + of a table, leaving a zero-column table. This is an extension from SQL92, + which disallows zero-column tables. + </para> </refsect2> </refsect1> diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml index 6d67f22a6b9..db51a26469f 100644 --- a/doc/src/sgml/ref/create_table.sgml +++ b/doc/src/sgml/ref/create_table.sgml @@ -1,5 +1,5 @@ <!-- -$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_table.sgml,v 1.59 2002/11/21 23:34:43 petere Exp $ +$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_table.sgml,v 1.60 2002/12/16 19:08:25 tgl Exp $ PostgreSQL documentation --> @@ -915,6 +915,19 @@ CREATE ASSERTION <replaceable>name</replaceable> CHECK ( <replaceable>condition< standard. </para> </refsect2> + + <refsect2> + <title>Zero-column tables</title> + + <para> + <productname>PostgreSQL</productname> allows a table of no columns + to be created (for example, <literal>CREATE TABLE foo();</>). This + is an extension from the SQL standard, which does not allow zero-column + tables. Zero-column tables are not in themselves very useful, but + disallowing them creates odd special cases for <command>ALTER TABLE + DROP COLUMN</>, so it seems cleaner to ignore this spec restriction. + </para> + </refsect2> </refsect1> |