column size in libpq

Started by Piotr Filipczukalmost 21 years ago2 messagesgeneral
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#1Piotr Filipczuk
filip@oeiizk.waw.pl

How to determinate column size in query in libpq? Especially when column
is declared for exapmle as varchar(64). PQfsize return -1 which mean
that is variable and PQfmod returns 68.

Piotr Filipczuk

#2John DeSoi
desoi@pgedit.com
In reply to: Piotr Filipczuk (#1)
Re: column size in libpq

On Apr 25, 2005, at 4:53 AM, Piotr Filipczuk wrote:

How to determinate column size in query in libpq? Especially when
column is declared for exapmle as varchar(64). PQfsize return -1
which mean that is variable and PQfmod returns 68.

68 - 4 is the correct size for varchar(64). There is 4 bytes of
overhead included in the return value.

If you are trying to do something like column formatting where you need
to know the longest length, maybe take a look at the psql source and
see how it works there.

John DeSoi, Ph.D.
http://pgedit.com/
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