Обсуждение: Type Inheritance

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Type Inheritance

От
"Andrew Thorley"
Дата:
Does anyone know how to implement type inheritance in postgresql? in oracle you just use the word UNDER in ur code i.e:

CREATE TYPE test2_UDT UNDER test1_UDT AS (abc INT);

any ideas?

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Re: Type Inheritance

От
Tom Lane
Дата:
"Andrew Thorley" <andrew.thorley@linuxmail.org> writes:
> Does anyone know how to implement type inheritance in postgresql? in oracle you just use the word UNDER in ur code
i.e:
> CREATE TYPE test2_UDT UNDER test1_UDT AS (abc INT);

If you had said what this *does*, we might be better able to help.

But take a look at CREATE DOMAIN, as well as the INHERITS and LIKE
options in CREATE TABLE.  Some part of that might be close to what
you are looking for.
        regards, tom lane


Re: Type Inheritance

От
"Andrew Thorley"
Дата:
hi tom thanks for reply.

im trying to provide inheritance for data types (domains), not tables. i will look into the syntax associated with
domainsas data types does not include an inheritance function (or so i think). 

regards andy.


----- Original Message -----
From: "Tom Lane" <tgl@sss.pgh.pa.us>
To: "Andrew Thorley" <andrew.thorley@linuxmail.org>
Subject: Re: [SQL] Type Inheritance
Date: Fri, 26 Nov 2004 13:14:07 -0500

>
> "Andrew Thorley" <andrew.thorley@linuxmail.org> writes:
> > Does anyone know how to implement type inheritance in postgresql? in oracle you just use the word UNDER in ur code
i.e:
> > CREATE TYPE test2_UDT UNDER test1_UDT AS (abc INT);
>
> If you had said what this *does*, we might be better able to help.
>
> But take a look at CREATE DOMAIN, as well as the INHERITS and LIKE
> options in CREATE TABLE.  Some part of that might be close to what
> you are looking for.
>
>             regards, tom lane
>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: the planner will ignore your desire to choose an index scan if your
>       joining column's datatypes do not match
>

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Re: Type Inheritance

От
"Andrew Thorley"
Дата:
"If you had said what this *does*, we might be better able to help"

basically i have a series of types (or data types), of which one is the root and each of the other types appear under
theroot as in generalisation/specialisation style, inheriting the above types attributes etc. this is what im trying to
achieve,although at present, to no avail :( 


----- Original Message -----
From: "Andrew Thorley" <andrew.thorley@linuxmail.org>
To: "Tom Lane" <tgl@sss.pgh.pa.us>
Subject: Re: [SQL] Type Inheritance
Date: Sat, 27 Nov 2004 22:04:55 +0800

>
> hi tom thanks for reply.
>
> im trying to provide inheritance for data types (domains), not tables. i will look into the syntax associated with
domainsas data types does not include an inheritance function (or so i think). 
>
> regards andy.
>
>
> ----- Original Message -----
> From: "Tom Lane" <tgl@sss.pgh.pa.us>
> To: "Andrew Thorley" <andrew.thorley@linuxmail.org>
> Subject: Re: [SQL] Type Inheritance
> Date: Fri, 26 Nov 2004 13:14:07 -0500
>
> >
> > "Andrew Thorley" <andrew.thorley@linuxmail.org> writes:
> > > Does anyone know how to implement type inheritance in postgresql? in oracle you just use the word UNDER in ur
codei.e: 
> >
> CREATE TYPE test2_UDT UNDER test1_UDT AS (abc INT);
> >
> > If you had said what this *does*, we might be better able to help.
> >
> > But take a look at CREATE DOMAIN, as well as the INHERITS and LIKE
> > options in CREATE TABLE.  Some part of that might be close to what
> > you are looking for.
> >
> >             regards, tom lane
> >
> > ---------------------------(end of broadcast)---------------------------
> > TIP 9: the planner will ignore your desire to choose an index scan if your
> >       joining column's datatypes do not match
> >
>
> --
> ______________________________________________
> Check out the latest SMS services @ http://www.linuxmail.org
> This allows you to send and receive SMS through your mailbox.
>
>
> Powered by Outblaze
>
> ---------------------------(end of broadcast)---------------------------
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>

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