diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/ref/alter_table.sgml | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml index f5f22cb85dd..eb769468c66 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 1.26 2001/09/03 12:57:49 petere Exp $ +$Header: /cvsroot/pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.27 2001/09/07 21:57:53 momjian Exp $ Postgres documentation --> @@ -211,9 +211,9 @@ ALTER TABLE <replaceable class="PARAMETER">table</replaceable> </para> <para> - In the current implementation, only FOREIGN KEY and CHECK constraints can - be added to a table. To create a unique constraint, create - a unique index (see <xref linkend="SQL-CREATEINDEX" + In the current implementation, only UNIQUE, FOREIGN KEY and CHECK constraints can + be added to a table. To create a primary constraint, create + a unique, not null index (see <xref linkend="SQL-CREATEINDEX" endterm="SQL-CREATEINDEX-title">). </para> @@ -297,6 +297,13 @@ ALTER TABLE distributors DROP CONSTRAINT zipchk ALTER TABLE distributors ADD CONSTRAINT distfk FOREIGN KEY (address) REFERENCES addresses(address) MATCH FULL </programlisting> </para> + + <para> + To add a (multi-column) unique constraint to a table: + <programlisting> +ALTER TABLE distributors ADD CONSTRAINT dist_id_zipcode_key UNIQUE (dist_id, zipcode) + </programlisting> + </para> </refsect1> <refsect1 id="R1-SQL-ALTERTABLE-3"> |