Re: How to compare the results of two queries? - Mailing list pgsql-general

From Igor Neyman
Subject Re: How to compare the results of two queries?
Date
Msg-id A76B25F2823E954C9E45E32FA49D70EC4281FA98@mail.corp.perceptron.com
Whole thread Raw
In response to How to compare the results of two queries?  (Juan Daniel Santana Rodés<jdsantana@estudiantes.uci.cu>)
Responses Re: How to compare the results of two queries?
Re: How to compare the results of two queries?
List pgsql-general

> -----Original Message-----
> From: Juan Daniel Santana Rodés [mailto:jdsantana@estudiantes.uci.cu]
> Sent: Tuesday, September 17, 2013 11:54 AM
> To: Igor Neyman
> Subject: Re: [GENERAL] How to compare the results of two queries?
> 
> El 17/09/13 11:27, Igor Neyman escribió:
> > create or replace function compare(sql1 character varying, sql2
> > character  varying) returns boolean as $body$ Declare lCount int := 0;
> > Begin
> >
> > EXECUTE 'SELECT COUNT(Res.*) FROM (  (' || sql1 || ' EXCEPT ' || sql2
> > || ') UNION (' || sql2 || ' EXCEPT ' || sql1 || ') ) Res' INTO lCount; IF (lCount
> = 0)
> >    RETURN TRUE;
> > ELSE
> >    RETURN FALSE;
> > END IF;
> >
> > End;
> > $body$ language 'plpgsql';
> 
> Hi, thank for your help...
> I'm trying to execute your code but, when I run the the sentence, it throw a
> exception.
> For example, I run this line...
> 
> select compare('select * from point limit 2', 'select * from point');
> 
> And, postgres throw the follow exceptio...
> 
> ERROR:  syntax error at or near "EXCEPT"
> LINE 1: ...COUNT(Res.*) FROM (  (select * from point limit 2 EXCEPT sel...
>                                                               ^
> QUERY:  SELECT COUNT(Res.*) FROM (  (select * from point limit 2 EXCEPT
> select * from point) UNION (select * from point EXCEPT select * from point
> limit 2) ) Res
> CONTEXT:  PL/pgSQL function "compare" line 5 at EXECUTE statement
> 
> ********** Error **********
> 
> ERROR: syntax error at or near "EXCEPT"
> Estado SQL:42601
> Contexto:PL/pgSQL function "compare" line 5 at EXECUTE statement
> 

"limit 2" does not work with "EXCEPT".

In the future reply to the list ("Reply All") in order to keep the list in the conversation.

Regards,
Igor Neyman


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