doc: Add PERIOD to ALTER TABLE reference docs

Commit 89f908a6d0a documented foreign keys with PERIOD in the CREATE
TABLE docs, but not in ALTER TABLE.  This commit adds the new syntax
to the ALTER TABLE docs.

Author: Paul A. Jungwirth <[email protected]>
Discussion: https://www.postgresql.org/message-id/57ea0668-5205-426e-b934-efc89f2186c2@illuminatedcomputing.com

diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml
index ff7f4e43f0b2c7ffde694c4ae11075726bcb429b..c8f7ab7d9563145c3be08fedcf407002c5439490 100644 (file)
--- a/doc/src/sgml/ref/alter_table.sgml
+++ b/doc/src/sgml/ref/alter_table.sgml
@@ -118,7 +118,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
   UNIQUE [ NULLS [ NOT ] DISTINCT ] ( <replaceable class="parameter">column_name</replaceable> [, ... ] [, <replaceable class="parameter">column_name</replaceable> WITHOUT OVERLAPS ] ) <replaceable class="parameter">index_parameters</replaceable> |
   PRIMARY KEY ( <replaceable class="parameter">column_name</replaceable> [, ... ] [, <replaceable class="parameter">column_name</replaceable> WITHOUT OVERLAPS ] ) <replaceable class="parameter">index_parameters</replaceable> |
   EXCLUDE [ USING <replaceable class="parameter">index_method</replaceable> ] ( <replaceable class="parameter">exclude_element</replaceable> WITH <replaceable class="parameter">operator</replaceable> [, ... ] ) <replaceable class="parameter">index_parameters</replaceable> [ WHERE ( <replaceable class="parameter">predicate</replaceable> ) ] |
-  FOREIGN KEY ( <replaceable class="parameter">column_name</replaceable> [, ... ] ) REFERENCES <replaceable class="parameter">reftable</replaceable> [ ( <replaceable class="parameter">refcolumn</replaceable> [, ... ] ) ]
+  FOREIGN KEY ( <replaceable class="parameter">column_name</replaceable> [, ... ] [, PERIOD <replaceable class="parameter">column_name</replaceable> ] ) REFERENCES <replaceable class="parameter">reftable</replaceable> [ ( <replaceable class="parameter">refcolumn</replaceable> [, ... ]  [, PERIOD <replaceable class="parameter">refcolumn</replaceable> ] ) ]
     [ MATCH FULL | MATCH PARTIAL | MATCH SIMPLE ] [ ON DELETE <replaceable class="parameter">referential_action</replaceable> ] [ ON UPDATE <replaceable class="parameter">referential_action</replaceable> ] }
 [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]