Thread: What's wrong with this function

What's wrong with this function

From
Najm Hashmi
Date:
Hi all,Here  is a plpgsql function:
flipr'#create function test_cur() returns text as'
flipr'# declare
flipr'#  mycur  cursor for select title from songs where song_id=10;
flipr'#  usr        record;
flipr'#  results    text;
flipr'# begin
flipr'#  open mycur;
flipr'#  fetch next from mycur into usr;
flipr'#  close mycur;
flipr'#  results:= usr.title;
flipr'#
flipr'# end;
flipr'# ' language 'plpgsql';
CREATE
flipr=# select test_cur() as Title;
NOTICE:  plpgsql: ERROR during compile of test_cur near line 2
ERROR:  parse error at or near "cursor"

What I am doing wrong?
Thanks in advance for your help.
Regards, Najm




Re: What's wrong with this function

From
Jie Liang
Date:
I just know you can use implict cursor inside the plpgsql
e.g
declare
rec record;
begin 
FOR rec IN select_clause LOOP    statements
END LOOP;
end;


Jie LIANG

St Bernard Software
Internet Products Inc.

10350 Science Center Drive
Suite 100, San Diego, CA 92121
Office:(858)320-4873

jliang@ipinc.com
www.ipinc.com

On Sat, 10 Feb 2001, Najm Hashmi wrote:

> Hi all,
>  Here  is a plpgsql function:
> flipr'#create function test_cur() returns text as'
> flipr'# declare
> flipr'#  mycur  cursor for select title from songs where song_id=10;
> flipr'#  usr        record;
> flipr'#  results    text;
> flipr'# begin
> flipr'#  open mycur;
> flipr'#  fetch next from mycur into usr;
> flipr'#  close mycur;
> flipr'#  results:= usr.title;
> flipr'#
> flipr'# end;
> flipr'# ' language 'plpgsql';
> CREATE
> flipr=# select test_cur() as Title;
> NOTICE:  plpgsql: ERROR during compile of test_cur near line 2
> ERROR:  parse error at or near "cursor"
> 
> What I am doing wrong?
> Thanks in advance for your help.
> Regards, Najm
> 
> 



Re: What's wrong with this function

From
Najm Hashmi
Date:
Jie Liang wrote:

> I just know you can use implict cursor inside the plpgsql
> e.g
> declare

result text;
tcount int4;

>
> rec record;
> begin
> FOR rec IN select_clause LOOP
>      statements
> END LOOP;
> end;
>

Thank you Jie for your help. I am bit confused about how it works. I want for
each row , obtained by select statment,  get certain values and then do some
calculations and out put that resulst  egfor rec IN select title, dcount from songs where  artist='xyz'
tcount:=tcount+rec.dcount;
 
END LOOP;return tcount;
would this work ?
Thanks again for your help.
Regards, Najm




Re: What's wrong with this function

From
Date:
the select query returns the first row to rec. You can then access its values with:
rec.field_name
at END LOOP it jumps back to FOR checks to see if there any more rows and if so moves to the next row and repeats the
loop.
 
It also looks like your missing a LOOP keyword at the end of the FOR line.
Here is an example that works.

CREATE FUNCTION get_children (integer) RETURNS integer AS
'
� � DECLARE
� � � � pnode_parent ALIAS FOR $1;
� � � � rec RECORD;
� � BEGIN
� � � � FOR rec IN SELECT * FROM �tree_adjacency_matrix WHERE node_parent = pnode_parent LOOP
� � � � � � INSERT INTO test (node1, node2) VALUES(stm.node_child, .rec.node_parent);
� � � � END LOOP;
� � � � RETURN 0;
� � END;
'LANGUAGE 'plpgsql'

Mark
On Saturday 10 February 2001 18:04, Najm Hashmi wrote:
> Hi all,
>  Here  is a plpgsql function:
> flipr'#create function test_cur() returns text as'
> flipr'# declare
> flipr'#  mycur  cursor for select title from songs where song_id=10;
> flipr'#  usr        record;
> flipr'#  results    text;
> flipr'# begin
> flipr'#  open mycur;
> flipr'#  fetch next from mycur into usr;
> flipr'#  close mycur;
> flipr'#  results:= usr.title;
> flipr'#
> flipr'# end;
> flipr'# ' language 'plpgsql';
> CREATE
> flipr=# select test_cur() as Title;
> NOTICE:  plpgsql: ERROR during compile of test_cur near line 2
> ERROR:  parse error at or near "cursor"
>
> What I am doing wrong?
> Thanks in advance for your help.
> Regards, Najm


Re: What's wrong with this function

From
Jie Liang
Date:
Try:
create function foo(text) returns int4 as '
delcaretcount int4:=0;
beginfor rec IN select title, dcount from songs where artist=$1 LOOP    tcount:= tcount+rec.dcount;END LOOP;return
tcount;
end;
' language 'plpgsql';


call it by:

db> select foo('Najm Hashmi');

it will return how many songs of 'Najm Hashmi' in your database.


Jie LIANG

St. Bernard Software
Internet Products Inc.

10350 Science Center Drive
Suite 100, San Diego, CA 92121
Office:(858)320-4873

jliang@ipinc.com
www.stbernard.com
www.ipinc.com

On Sat, 10 Feb 2001, Najm Hashmi wrote:

> Jie Liang wrote:
> 
> > I just know you can use implict cursor inside the plpgsql
> > e.g
> > declare
> 
> result text;
> tcount int4;
> 
> >
> > rec record;
> > begin
> > FOR rec IN select_clause LOOP
> >      statements
> > END LOOP;
> > end;
> >
> 
> Thank you Jie for your help. I am bit confused about how it works. I want for
> each row , obtained by select statment,  get certain values and then do some
> calculations and out put that resulst  eg



>  for rec IN select title, dcount from songs where  artist='xyz'
>                  tcount:= tcount+rec.dcount;
> END LOOP;
>  return tcount;
> would this work ?
> Thanks again for your help.
> Regards, Najm
> 
> 



Re: What's wrong with this function

From
mark proctor
Date:
the select query returns the first row to rec. You can then access its values with:
rec.field_name
at END LOOP it jumps back to FOR checks to see if there any more rows and if so moves to the next row and repeats the
loop.
 
It also looks like your missing a LOOP keyword at the end of the FOR line.
Here is an example that works.

CREATE FUNCTION get_children (integer) RETURNS integer AS
'   DECLARE       pnode_parent ALIAS FOR $1;       rec RECORD;   BEGIN       FOR rec IN SELECT * FROM
tree_adjacency_matrixWHERE node_parent = pnode_parent LOOP           INSERT INTO test (node1, node2)
VALUES(stm.node_child,.rec.node_parent);       END LOOP;       RETURN 0;   END;
 
'LANGUAGE 'plpgsql'

Mark

On Saturday 10 February 2001 20:23, Najm Hashmi wrote:
> Jie Liang wrote:
> > I just know you can use implict cursor inside the plpgsql
> > e.g
> > declare
>
> result text;
> tcount int4;
>
> > rec record;
> > begin
> > FOR rec IN select_clause LOOP
> >      statements
> > END LOOP;
> > end;
>
> Thank you Jie for your help. I am bit confused about how it works. I want
> for each row , obtained by select statment,  get certain values and then do
> some calculations and out put that resulst  eg
>  for rec IN select title, dcount from songs where  artist='xyz'
>                  tcount:= tcount+rec.dcount;
> END LOOP;
>  return tcount;
> would this work ?
> Thanks again for your help.
> Regards, Najm