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Thread: Dynamic File Name for COPY TO in Stored Procedure

Dynamic File Name for COPY TO in Stored Procedure

From
"Carlos Oliva"
Date:

Hi,

What would it be the correct format for using a variable in a stored procedure that uses COPY TO?

 

I have the current stored procedure:

CREATE FUNCTION Table_To_File(text) RETURNS void AS $delimeter$

   COPY (SELECT * FROM table_to_xml('table', true, false, '')) TO '$1' WITH CSV QUOTE ' ';

$delimeter$

LANGUAGE SQL;

 

When I run the stored procedure: psql –d <db name> -c “select Table_To_File(‘some_absolute_file_name’)”;  I get the error that I must use absolute file names.

 

When I replace TO ‘$1’ with TO ‘/tmp/toto.xml’, the stored procedure runs fine and creates the local file.

 

I have tried several different ways to escape the $1 variable to no avail.  At best, I get the same error.

 

 




Re: Dynamic File Name for COPY TO in Stored Procedure

From
Adrian Klaver
Date:
On Thursday, February 23, 2012 6:42:53 am Carlos Oliva wrote:
> Hi,
> What would it be the correct format for using a variable in a stored
> procedure that uses COPY TO?
>
> I have the current stored procedure:
> CREATE FUNCTION Table_To_File(text) RETURNS void AS $delimeter$
>    COPY (SELECT * FROM table_to_xml('table', true, false, '')) TO '$1'
> WITH CSV QUOTE ' ';
> $delimeter$
> LANGUAGE SQL;
>
> When I run the stored procedure: psql -d <db name> -c "select
> Table_To_File('some_absolute_file_name')";  I get the error that I must
> use absolute file names.
>
> When I replace TO '$1' with TO '/tmp/toto.xml', the stored procedure
> runs fine and creates the local file.
>
> I have tried several different ways to escape the $1 variable to no
> avail.  At best, I get the same error.

You will need to switch to using plpgsql and its EXECUTE statement to build the COPY
statement :

http://www.postgresql.org/docs/9.0/interactive/plpgsql-statements.html#PLPGSQL-STATEMENTS-EXECUTING-DYN


--
Adrian Klaver
adrian.klaver@gmail.com

Re: Dynamic File Name for COPY TO in Stored Procedure

From
"Carlos Oliva"
Date:
That worked.  Thank you Adrian


-----Original Message-----
From: Adrian Klaver [mailto:adrian.klaver@gmail.com]
Sent: Thursday, February 23, 2012 9:58 AM
To: pgsql-general@postgresql.org
Cc: Carlos Oliva
Subject: Re: [GENERAL] Dynamic File Name for COPY TO in Stored Procedure

On Thursday, February 23, 2012 6:42:53 am Carlos Oliva wrote:
> Hi,
> What would it be the correct format for using a variable in a stored
> procedure that uses COPY TO?
>
> I have the current stored procedure:
> CREATE FUNCTION Table_To_File(text) RETURNS void AS $delimeter$
>    COPY (SELECT * FROM table_to_xml('table', true, false, '')) TO '$1'
> WITH CSV QUOTE ' ';
> $delimeter$
> LANGUAGE SQL;
>
> When I run the stored procedure: psql -d <db name> -c "select
> Table_To_File('some_absolute_file_name')";  I get the error that I
must
> use absolute file names.
>
> When I replace TO '$1' with TO '/tmp/toto.xml', the stored procedure
> runs fine and creates the local file.
>
> I have tried several different ways to escape the $1 variable to no
> avail.  At best, I get the same error.

You will need to switch to using plpgsql and its EXECUTE statement to
build the COPY
statement :

http://www.postgresql.org/docs/9.0/interactive/plpgsql-statements.html#P
LPGSQL-STATEMENTS-EXECUTING-DYN


--
Adrian Klaver
adrian.klaver@gmail.com