Thomas Swan wrote: >I think I may have asked this before... If I did I'm sorry, but maybe this >attempt, assuming a
priorone, may be a little more clear. > >create table foo (id int8); >create table bar1 (name text) inherits (foo);
>createtable bar2 (data text) inherits (foo); >create table hybrid ( ) inherits (bar1, bar2); > >INSERT INTO foo VALUES
(1);>INSERT INTO bar1 VALUES (2,'myname'); >INSERT INTO bar2 VALUES (3,'mydata'); >INSERT INTO hybrid VALUES
(4,'morename','moredata');> > >I want to do a SELECT * FROM foo*; but I only get the 'id' column as in : > >id >--- >
1> 2 > 3 > 4
This is correct in object-oriented theory. foo only knows about its own
features; it does not know about additional features of its descendants,
nor should it.
>What would be the query to get the following table or a magical way to >expand children? > >I had originally hoped
thatSELECT * FROM foo* would yield the following, >but it's not so. > >id | name | data
>---+------------+-------------> 1 | null | null > 2 | 'myname' | null > 3 | null | 'mydata' > 4 |
'morename'| 'moredata'
You need to use a UNION of the four tables, with nulls
supplied where necessary:
select * from hybrid -- specify first to establish the -- column
types
union select id, null, null from foo
union select id, name, null from bar1
union select id, null, data from bar2;
Unfortunately, you can't make this a view, because views of unions are
not yet supported.
--
Oliver Elphick Oliver.Elphick@lfix.co.uk
Isle of Wight http://www.lfix.co.uk/oliver
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======================================== "But the wisdom that is from above is first pure, then peaceable,
gentle,and easy to be intreated, full of mercy and good fruits, without partiality, and without hypocrisy."
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