Search Postgresql Archives

possible bug with inheritance?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi,

Our documentation says:
"All check constraints and not-null constraints on a parent table are
automatically inherited by its children."

Okay, this works as expected:

test=# create table parent (name text primary key);
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "parent_pkey" for table "parent"
CREATE TABLE
test=*# create table child (age int) inherits (parent) ;
CREATE TABLE
test=*# \d child
     Table "public.child"
 Column |  Type   | Modifiers
--------+---------+-----------
 name   | text    | not null
 age    | integer |
Inherits: parent


Nice, the 'not null' constraint is in the child-table.


test=*# rollback;
ROLLBACK
test=# create table parent (name text);
CREATE TABLE
test=*# create table child (age int) inherits (parent) ;
CREATE TABLE
test=*# alter table parent add primary key (name);
NOTICE:  ALTER TABLE / ADD PRIMARY KEY will create implicit index "parent_pkey" for table "parent"
ALTER TABLE
test=*# \d child
     Table "public.child"
 Column |  Type   | Modifiers
--------+---------+-----------
 name   | text    |
 age    | integer |
Inherits: parent


Doh, there isn't the 'not null' - modifier. The parent-table contains
this modifier as part of the primary key - definition.


Other test:

test=# create table parent (name text);
CREATE TABLE
test=*# create table child (age int) inherits (parent) ;
CREATE TABLE
test=*# alter table parent alter column name set not null;
ALTER TABLE
test=*# \d child
     Table "public.child"
 Column |  Type   | Modifiers
--------+---------+-----------
 name   | text    | not null
 age    | integer |
Inherits: parent


Okay, we have again the 'not null'.


I think, that's not really clearly. In some case the 'not null' -
constraint are in the child-table, in other case they are not.

Version 8.4.2.

Bug, feature? What have i overlooked?


Andreas
-- 
Andreas Kretschmer
Kontakt:  Heynitz: 035242/47150,   D1: 0160/7141639 (mehr: -> Header)
GnuPG: 0x31720C99, 1006 CCB4 A326 1D42 6431  2EB0 389D 1DC2 3172 0C99

-- 
Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Postgresql Jobs]     [Postgresql Admin]     [Postgresql Performance]     [Linux Clusters]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Postgresql & PHP]     [Yosemite]
  Powered by Linux