Обсуждение: How to handle nested record data.

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How to handle nested record data.

От
yi huang
Дата:
I'm porting a oracle function to postgresql, which has signature like this:

  FUNCTION foo
     ( seq IN varchar
     , somerow OUT SomeTable
     , otherinfo OUT varchar
     )

It's easy to port this function itself to postgresql, but i have problem to execute this function and assign the results into variables:

  SELECT (foo(seq)).* INTO (v_somerow, v_otherinfo);

It complains v_somerow can not be row type.

How to handle the result of function foo?

Best regards.
YiHuang.

Re: How to handle nested record data.

От
Pavel Stehule
Дата:
Hello

create or replace function call_foo()
returns void as $$
declare r record;
begin
  r := foo('Hello');
  raise notice ''% %', r.somerow, r.otherinfo;
end;
$$ language plpgsql;

regards

Pavel

2012/5/30 yi huang <yi.codeplayer@gmail.com>:
> I'm porting a oracle function to postgresql, which has signature like this:
>
>   FUNCTION foo
>      ( seq IN varchar
>      , somerow OUT SomeTable
>      , otherinfo OUT varchar
>      )
>
> It's easy to port this function itself to postgresql, but i have problem to
> execute this function and assign the results into variables:
>
>   SELECT (foo(seq)).* INTO (v_somerow, v_otherinfo);
>
> It complains v_somerow can not be row type.
>
> How to handle the result of function foo?
>
> Best regards.
> YiHuang.

Re: How to handle nested record data.

От
yi huang
Дата:
Thanks for you quick reply, but i need to take this returned row in another pgsql function and do further processing.

On Wed, May 30, 2012 at 11:21 AM, Pavel Stehule <pavel.stehule@gmail.com> wrote:
Hello

create or replace function call_foo()
returns void as $$
declare r record;
begin
 r := foo('Hello');
 raise notice ''% %', r.somerow, r.otherinfo;
end;
$$ language plpgsql;

regards

Pavel

2012/5/30 yi huang <yi.codeplayer@gmail.com>:
> I'm porting a oracle function to postgresql, which has signature like this:
>
>   FUNCTION foo
>      ( seq IN varchar
>      , somerow OUT SomeTable
>      , otherinfo OUT varchar
>      )
>
> It's easy to port this function itself to postgresql, but i have problem to
> execute this function and assign the results into variables:
>
>   SELECT (foo(seq)).* INTO (v_somerow, v_otherinfo);
>
> It complains v_somerow can not be row type.
>
> How to handle the result of function foo?
>
> Best regards.
> YiHuang.



--
http://yi-programmer.com/

Re: How to handle nested record data.

От
yi huang
Дата:
On Wed, May 30, 2012 at 12:36 PM, yi huang <yi.codeplayer@gmail.com> wrote:
Thanks for you quick reply, but i need to take this returned row in another pgsql function and do further processing.

Sorry, i was misunderstood, i get it now, just use a record type, thanks very much.
 


On Wed, May 30, 2012 at 11:21 AM, Pavel Stehule <pavel.stehule@gmail.com> wrote:
Hello

create or replace function call_foo()
returns void as $$
declare r record;
begin
 r := foo('Hello');
 raise notice ''% %', r.somerow, r.otherinfo;
end;
$$ language plpgsql;

regards

Pavel

2012/5/30 yi huang <yi.codeplayer@gmail.com>:
> I'm porting a oracle function to postgresql, which has signature like this:
>
>   FUNCTION foo
>      ( seq IN varchar
>      , somerow OUT SomeTable
>      , otherinfo OUT varchar
>      )
>
> It's easy to port this function itself to postgresql, but i have problem to
> execute this function and assign the results into variables:
>
>   SELECT (foo(seq)).* INTO (v_somerow, v_otherinfo);
>
> It complains v_somerow can not be row type.
>
> How to handle the result of function foo?
>
> Best regards.
> YiHuang.



--
http://yi-programmer.com/



--
http://yi-programmer.com/

Re: How to handle nested record data.

От
yi huang
Дата:
On Wed, May 30, 2012 at 11:21 AM, Pavel Stehule <pavel.stehule@gmail.com> wrote:
Hello

create or replace function call_foo()
returns void as $$
declare r record;
begin
 r := foo('Hello');
 raise notice ''% %', r.somerow, r.otherinfo;
end;
$$ language plpgsql;

It turns out i also need to define a type for the result record of `foo`, because record can't reveal the structure of the result (it complains: record "r" has no field "somerow").
I have to created this type:

  create type foo_result as (somerow  SomeTable, otherinfo  varchar);

then change `r record;` to `r  foo_result;` , no need change `foo` itself, and it works now.

I don't know is this the best way to do this though.
 

regards

Pavel

2012/5/30 yi huang <yi.codeplayer@gmail.com>:
> I'm porting a oracle function to postgresql, which has signature like this:
>
>   FUNCTION foo
>      ( seq IN varchar
>      , somerow OUT SomeTable
>      , otherinfo OUT varchar
>      )
>
> It's easy to port this function itself to postgresql, but i have problem to
> execute this function and assign the results into variables:
>
>   SELECT (foo(seq)).* INTO (v_somerow, v_otherinfo);
>
> It complains v_somerow can not be row type.
>
> How to handle the result of function foo?
>
> Best regards.
> YiHuang.



--
http://yi-programmer.com/

Re: How to handle nested record data.

От
Pavel Stehule
Дата:
2012/5/30 yi huang <yi.codeplayer@gmail.com>:
> On Wed, May 30, 2012 at 11:21 AM, Pavel Stehule <pavel.stehule@gmail.com>
> wrote:
>>
>> Hello
>>
>> create or replace function call_foo()
>> returns void as $$
>> declare r record;
>> begin
>>  r := foo('Hello');
>>  raise notice ''% %', r.somerow, r.otherinfo;
>> end;
>> $$ language plpgsql;
>
>
> It turns out i also need to define a type for the result record of `foo`,
> because record can't reveal the structure of the result (it complains:
> record "r" has no field "somerow").
> I have to created this type:
>
>   create type foo_result as (somerow  SomeTable, otherinfo  varchar);
>
> then change `r record;` to `r  foo_result;` , no need change `foo` itself,
> and it works now.
>
> I don't know is this the best way to do this though.

best way is way that works :). Implementation of records and related
features is relative complex and not consistent all time - mainly when
function with OUT arguments is used. There are a issues - sometimes
cast is necessary, sometimes nested records can be accessed only to
first level (and for second levels you needs casts or auxiliary
variables) - so it works perfectly, but sometime is difficult to find
syntax that works.

Regards

Pavel
>
>>
>>
>> regards
>>
>> Pavel
>>
>> 2012/5/30 yi huang <yi.codeplayer@gmail.com>:
>> > I'm porting a oracle function to postgresql, which has signature like
>> > this:
>> >
>> >   FUNCTION foo
>> >      ( seq IN varchar
>> >      , somerow OUT SomeTable
>> >      , otherinfo OUT varchar
>> >      )
>> >
>> > It's easy to port this function itself to postgresql, but i have problem
>> > to
>> > execute this function and assign the results into variables:
>> >
>> >   SELECT (foo(seq)).* INTO (v_somerow, v_otherinfo);
>> >
>> > It complains v_somerow can not be row type.
>> >
>> > How to handle the result of function foo?
>> >
>> > Best regards.
>> > YiHuang.
>
>
>
>
> --
> http://yi-programmer.com/

Re: How to handle nested record data.

От
Sergey Konoplev
Дата:
On Wed, May 30, 2012 at 9:03 AM, yi huang <yi.codeplayer@gmail.com> wrote:
> It turns out i also need to define a type for the result record of `foo`,
> because record can't reveal the structure of the result (it complains:
> record "r" has no field "somerow").
> I have to created this type:
>
>   create type foo_result as (somerow  SomeTable, otherinfo  varchar);
>
> then change `r record;` to `r  foo_result;` , no need change `foo` itself,
> and it works now.
>
> I don't know is this the best way to do this though.

I am not sure my assumption is correct but have not you tried to do it like this

SELECT * FROM foo(seq) AS (somerow  SomeTable, otherinfo  varchar)

it will probably help to avoid creation of a separate type for the
function result.

>
>>
>>
>> regards
>>
>> Pavel
>>
>> 2012/5/30 yi huang <yi.codeplayer@gmail.com>:
>> > I'm porting a oracle function to postgresql, which has signature like
>> > this:
>> >
>> >   FUNCTION foo
>> >      ( seq IN varchar
>> >      , somerow OUT SomeTable
>> >      , otherinfo OUT varchar
>> >      )
>> >
>> > It's easy to port this function itself to postgresql, but i have problem
>> > to
>> > execute this function and assign the results into variables:
>> >
>> >   SELECT (foo(seq)).* INTO (v_somerow, v_otherinfo);
>> >
>> > It complains v_somerow can not be row type.
>> >
>> > How to handle the result of function foo?
>> >
>> > Best regards.
>> > YiHuang.
>
>
>
>
> --
> http://yi-programmer.com/



--
Sergey Konoplev

a database and software architect
http://www.linkedin.com/in/grayhemp

Jabber: gray.ru@gmail.com Skype: gray-hemp Phone: +79160686204