Date: Sun, 12 Dec 1999 15:18:57 +0100
From: Michael Meskes <meskes@postgresql.org>
To: Martin Jackson <mhjacks@nwa.quik.com>
Cc: pgsql-interfaces@postgresql.org
Subject: Re: [INTERFACES] ESQL/C Docs:  Request for code
Message-ID: <19991212151857.A548@fam-meskes.de>
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	pgsql-interfaces@postgresql.org
References: <3852B326.D68C6BE2@nwa.quik.com>
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	from mhjacks@nwa.quik.com on Sat, Dec 11, 1999 at 02:25:10PM -0600

On Sat, Dec 11, 1999 at 02:25:10PM -0600, Martin Jackson wrote:
> I am looking for examples of working ECPG code.  Partly I would like to

There are some in the source code under test/.

> see for myself how it works, but I would also be willing to write some
> documentation on it, which I would be willing to submit to the CVS tree.

Great. :-)

> I do not understand, for example, how to handle cursors in ECPG because
> I have not found any examples of doing so in the documentation I have. 
> Others have probably had the same problem.

Cursors are used in the test examples.

> I am familiar with the Informix ESQL/C implementation, if that matters.

It should be the same for the most part. I'm interested in hearing about all
differences you find.

> 1)  How do you set up a fetch operation?  Is there a nicer way to do it
> in EC without a cursor?  That is,
> 
> 	DECLARE foo CURSOR FOR
> 		SELECT * FROM bar
> 		WHERE baz = :bazval
> 
> 	{time passes}
> 
> 	FETCH foo INTO :bletch, :foo2;

SELECT * INTO :bletch, :Bazval FROM bar where baz = :bazval

> 2)  Can you PREPARE (i.e. cache) statements for later execution?
> 	EXEC SQL DELETE FROM foo
> 		WHERE baz = ?

Yes.

> 3)  Does Postgres directly support placeholders (?)?  I've used them in
> DBI, but I don't know whether that's some hack by the Postgres driver
> author or if it's an actual Postgres feature?

Yes. You can use it directly in statements you prepare.

> 4)  What kind of scope do declared cursors have?

I'm not exactly sure but I think it has to be the module i.e. source file.

> 5) (META-QUESTION):  Is ECPG suitable for a large system, i.e. an
> accounting system for a small business?

It should yes. If there is a problem ECPG will be fixed.

Michael
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