Reported lengths of char fields - psqlODBC

Linux Mint 18.3 x64 (base on Ubuntu 16.04 package base)
Postgresql v 9.5.14
unixODBC v2.3.1-4.1
psqlODBC v1:09.03.0300-1

I created a simple table containing one column of type character (n).
When I ask for the width of the column via (ODBC)SQLColAttribute function,
it answers (n*6) , so if defined as character(1) the call reports length 6,
character(2) reports 12, character(4) reports 24, etc.

I see the same kind of results when using a varchar(n) field (character
varying (2), etc ) as well .

Is this expected, or am I doing something wrong?



Re: Reported lengths of char fields - psqlODBC

By Clemens Ladisch at 02/09/2019 - 02:57

Bob Brodd wrote:
Please note that newer versions of the ODBC driver are backwards compatible,
and have bug fixes.

I guess you are asking not for SQL_DESC_LENGTH but SQL_DESC_OCTET_LENGTH?
The latter multiplies the column size (in characters) by the maximum possible
number of bytes per character, which is 4 in the Unicode driver, and 6 when
using UTF-8 as client encoding. (In driver version 9.6.3, the UTF-8 value
was corrected to 4.)