Re: pl/pgSQL sequence question - Mailing list pgsql-novice

From Stephen Shorrock
Subject Re: pl/pgSQL sequence question
Date
Msg-id sffd931b.075@pcmail.nerc-bas.ac.uk
Whole thread Raw
In response to pl/pgSQL sequence question  ("Stephen Shorrock" <smsh@bas.ac.uk>)
List pgsql-novice
Thanks for your response Tom,

I thought that you might like to know I've implemented you idea of using idcol SERIAL PRIMARY KEY, which is a really
goodtip. Although not in a function as I am unable to remove this durring the function call:  
ERROR:  RelationForgetRelation: relation 47527448 is still open
I can comment out the dropsequence command but this will leave a sequence debugtab_idcol_seq in the data base and I am
unableto run the procedure again before deleting this, so I placed the drop call at the start of the function.  It
thereforelooks like you can not create then drop a sequence in a function although you can drop then create one!? 

the offending code:-

CREATE or REPLACE FUNCTION debugMe(integer,integer) returns integer AS '   DECLARE      size alias for $1;
resolutionalias for $2;      createtable varchar(200);      dropseq varchar(200);      droptable varchar(200);
loadtablevarchar(200);   BEGIN      --sequence commands 
      dropseq := ''DROP SEQUENCE debugtab_idcol_seq'';
--executing the dropseq command here works?! (that's if the function has already beeen run!!)
      --table commands      createtable := ''CREATE TABLE debugtab(idcol SERIAL PRIMARY KEY, value int )'';
      droptable := ''DROP TABLE debugtab'';
      --insert data commands      loadtable := ''insert into debugtab(value) select 0 from data_flt where dfl_value > 0
limit''||size;      --A      --execute createseq;      --B      execute createtable;      --why can it not find
tmp_seq??     --C insert data, not a worry at the moment     execute loadtable;            --D do the major processing
         --Z clean up      execute droptable;      execute dropseq; --does not work here    return 0;   END;' LANGUAGE
'plpgsql';

>>> Tom Lane <tgl@sss.pgh.pa.us> 12/22/03 10:08PM >>>
"Stephen Shorrock" <smsh@bas.ac.uk> writes:
>       createtable := ''CREATE TABLE debugtab(idcol INTEGER PRIMARY KEY DEFAULT NEXTVAL(tmp_seq), value int )'';

>       --why can it not find tmp_seq??

You need quotes.  For mostly historic reasons, nextval takes a string
argument containing the name of the sequence, which is not what you
wrote here.

You could avoid messing directly with the sequence if you defined the
column as "idcol SERIAL PRIMARY KEY", instead.

            regards, tom lane


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