diff options
Diffstat (limited to 'doc/src/sgml/ref/alter_table.sgml')
| -rw-r--r-- | doc/src/sgml/ref/alter_table.sgml | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml index d6bf184d649..ab929728a7f 100644 --- a/doc/src/sgml/ref/alter_table.sgml +++ b/doc/src/sgml/ref/alter_table.sgml @@ -1,5 +1,5 @@ <!-- -$PostgreSQL: pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.98 2007/11/28 15:42:31 petere Exp $ +$PostgreSQL: pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.99 2008/05/09 23:32:03 tgl Exp $ PostgreSQL documentation --> @@ -713,7 +713,8 @@ ALTER TABLE table ALTER COLUMN anycol TYPE anytype; The <literal>TRIGGER</>, <literal>CLUSTER</>, <literal>OWNER</>, and <literal>TABLESPACE</> actions never recurse to descendant tables; that is, they always act as though <literal>ONLY</> were specified. - Adding a constraint can recurse only for <literal>CHECK</> constraints. + Adding a constraint can recurse only for <literal>CHECK</> constraints, + and is required to do so for such constraints. </para> <para> @@ -804,7 +805,7 @@ ALTER TABLE distributors ALTER COLUMN street DROP NOT NULL; </para> <para> - To add a check constraint to a table: + To add a check constraint to a table and all its children: <programlisting> ALTER TABLE distributors ADD CONSTRAINT zipchk CHECK (char_length(zipcode) = 5); </programlisting> @@ -818,6 +819,14 @@ ALTER TABLE distributors DROP CONSTRAINT zipchk; </para> <para> + To remove a check constraint from a table only: +<programlisting> +ALTER TABLE ONLY distributors DROP CONSTRAINT zipchk; +</programlisting> + (The check constraint remains in place for any child tables.) + </para> + + <para> To add a foreign key constraint to a table: <programlisting> ALTER TABLE distributors ADD CONSTRAINT distfk FOREIGN KEY (address) REFERENCES addresses (address) MATCH FULL; |