Re: How to convert SQL store procedure to Postgresql function

hi ,
whats wrong with this function , i am getting syntax error which is syntax error at or near "+="
LINE 13: set sql += ' bpoverlap, centredistance from vwchrcomparesit...
^
how this problem can be solved.
thanks

CREATE OR REPLACE FUNCTION getsitesbytfid(user_datadetailid int, kb_id int,bp_overlap int,chr_ varchar ,centre_distance int)
RETURNS table(chr_u varchar,start_u int,end_u int,region_size_u int,chr_kb varchar,start_kb int ,end_kb int,region_size_kb int,bpoverlap int,centredistance int)
as
$BODY$
DECLARE sql varchar ;
BEGIN

if centre_distance= NULL THEN
set centre_distance = 1;

set sql = 'select chr_u, start_u, end_u, regionsize_u, chr_kb, start_kb, end_kb, regionsize_kb, ';
set sql += ' bpoverlap, centredistance from vwchrcomparesites where userdatadetailid=' + user_datadetailid
set sql += ' and bpoverlap>=' + bp_overlap
set sql += ' and kbid=' + kb_id
if chr_<>'all' and isnull(chr_,'')<>''
set @sql += ' and chr_u=''' + chr_ +''''
if (centre_distance<>'')
set sql += ' and (centredistance<=' + centre_distance + ' or ' + centre_distance + '=1) '
set sql += ' order by chr_u, start_u'

exec(sql)
end;
$BODY$
language plpgsql;

________________________________
From: Filip Rembiałkowski <plk(dot)zuber(at)gmail(dot)com>
To: Rehan Saleem <pk_rehan(at)yahoo(dot)com>
Cc: "pgsql-sql(at)postgresql(dot)org" <pgsql-sql(at)postgresql(dot)org>
Sent: Tuesday, February 28, 2012 3:36 PM
Subject: Re: [SQL] How to convert SQL store procedure to Postgresql function

On Tue, Feb 28, 2012 at 9:50 AM, Rehan Saleem <pk_rehan(at)yahoo(dot)com> wrote:
> hi ,
> how can i convert this sql store procedure to postgresql function , i shall
> be very thankful to you, as i am new to postgresql and i dont know how to
> handle this kind of store procedure in postgresql

Most people handle this with user-defined functions (UDF) written in
PL/PgSQL procedural language.

Try to read The Friendly Manual
http://www.postgresql.org/docs/current/static/sql-createfunction.html
http://www.postgresql.org/docs/current/static/plpgsql.html

Don't worry - all Transact-SQL constructs have their equivalent.

Just start rewriting your function and begin asking specific questions
here... People will help.

I would begin with

create or replace function sp_GetUserByID( in_UserId varchar(50), ...)
returns varchar(50)
language plpgsql as $$
declare
...
begin
...
return somevariable;
end;
$$;

HTH,
Filip