limited varchar for ogr-pg driver

[martinl]

Hi,

currently OGR-PG driver doesn't allow to define fields with limited varchar type. If you define PRECISION=YES for columns of character type OGR uses CHAR(width) otherwise VARCHAR. The attached patch defines VARCHAR(width) or VARCHAR when field width is not positive integer.

Better solution would be probably not to mix precision with char/varchar. In other words there would be new option USE_VARCHAR which would define if to use VARCHAR or CHAR. Option PRECISION would just control whether to use [VAR]CHAR(width) or just [VAR]CHAR. What do you think?

[Even Rouault]

There's no attached patch.

From what can I read from ​http://www.postgresql.org/docs/8.3/static/datatype-character.html (the Tip paragraph), there's no advantage in using the CHAR(width) variant rather than the VARCHAR(width) one. So it's perhaps not worth proposing an option to control the use of CHAR or VARCHAR. Paul, any thought ?

[martinl]

use varchar instead of char

[martinl]

Sorry, I have attached the patch few minutes ago. So could be CHAR replaced by VARCHAR as suggested in the patch?

[pramsey]

Yes, I think VARCHAR would be preferable over CHAR. I don't think there's any point in providing an option for forcing the use of CHAR.

[Even Rouault]

r22968 /trunk/gdal/ogr/ogrsf_frmts/pg/ogrpgtablelayer.cpp: PG: create field of type OFTString and width > 0, as VARCHAR(width) (rather than CHAR(width) before, #4202)

[Even Rouault]

r22969 /trunk/ (3 files in 3 dirs): Remove tab indentation of r22968 and also apply the change of typing from CHAR(n) to VARCHAR(n) for the PGDump driver (#4202)