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-rw-r--r--doc/src/sgml/ref/alter_table.sgml8
-rw-r--r--doc/src/sgml/ref/create_table.sgml15
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>