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Message-ID: <467696D7.2090703@terra.com.br>
Date: Mon, 18 Jun 2007 11:29:43 -0300
From: Ranieri Mazili <ranieri.oliveira@terra.com.br>
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To: pgsql-general@postgresql.org,  pgsql-sql@postgresql.org
Subject: Setting variable
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Hello,
I need to know why can't I do it?

CREATE OR REPLACE FUNCTION lost_hours_temp(date)
RETURNS text AS
$BODY$
DECLARE
    START_DATE date;
    END_DATE date;
    QUERY text;
BEGIN
    START_DATE := $1;
    END_DATE := START_DATE - interval '3 year';

The last line (END_DATE := START_DATE - interval '3 year';) generate the 
following error:

ERROR: operator is not unique: "unknown" / "unknown"
SQL state: 42725
Hint: Could not choose a best candidate operator. You may need to add 
explicit type casts.
Context: PL/pgSQL function "lost_hours_temp" line 10 at assignment

How can I solve it?

Thanks