[Qgis-user] manipulating shapefiles

[Yves Jacolin]

Le mercredi 23 décembre 2009 06:05:27, sunny74 a écrit :
> Hi,
>
> I have got several shapefiles from which I am able to display map using
> mapserver.
> But the problem is that it has a srid value of -1 i.e no projection.
> As a result of this several functionalities which uses geometry are not
> working.
> I think the default srid value is 4326.Pls confirm.
>
> I want to convert the srid value from -1 to 4326.
> How can I do this using QGIS?
> I know this is possible using GEOMEDIA Web 6.0.
>
> If anybody has any idea or tutorial regarding .shp manipulation using
> Geomedia pls send it across.
>
> Thanks for ur replies.
>
> sunny74
Hi,

You need to send an sql request to postgis to define SRID of your feature, such 
way:
SELECT setSrid(the_geom,4326) FROM myTable;

You may need to update geometry_column table as well.

I guess you can use some QGIS plugin to send such SQL request.

When you will import your data, don't forget to set up your srid configuration 
correctly to avoid this issue (if you forgot, you will get an -1 srid by 
default which means "unknown srid").

Regards,

Y.
-- 
Yves Jacolin

http://yjacolin.gloobe.org