[Qgis-user] Deleting a column from attribute table

Wed Jul 27 08:19:23 PDT 2011

Dear All,

            As a novice in QGIS, i created a column on an attribute which i dont want any more, pls can any experience person tell me how to delete the column.
Thanks
El-Oji

--- On Wed, 7/27/11, qgis-user-request at lists.osgeo.org <qgis-user-request at lists.osgeo.org> wrote:

From: qgis-user-request at lists.osgeo.org <qgis-user-request at lists.osgeo.org>
Subject: Qgis-user Digest, Vol 65, Issue 61
To: qgis-user at lists.osgeo.org
Date: Wednesday, July 27, 2011, 11:14 AM

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Today's Topics:

   1. Re: object labels (Andreas Neumann)
   2. RE: QGIS -> MySQL -> Mapserver ?? (Chris Green)
   3. RE: QGIS -> MySQL -> Mapserver ?? (Saber)
   4. DTclassifier is released (Maxim Dubinin)

----------------------------------------------------------------------

Message: 1
Date: Wed, 27 Jul 2011 11:00:01 +0200
From: Andreas Neumann <a.neumann at carto.net>
Subject: Re: [Qgis-user] object labels
To: <qgis-user at lists.osgeo.org>
Message-ID: <2634cc5e1e8f0d3a1c3ecba07210ba79 at carto.net>
Content-Type: text/plain; charset=UTF-8; format=flowed

Hi,

Currently, you have to create a new column. I usually create a view in 
Postgis for this purpose.

It is in on the wishlist that one can create a "virtual" column - not 
only for labeling, but also for map tips and perhaps symbolization. 
Until then you have to do it yourself.

Andreas

On Tue, 26 Jul 2011 22:51:34 +0200, Torsten Lange wrote:
> Hi,
>
> Is there a way just to print - lets say - the first four letters of a
> objects
> name? Or must I create a new row for that?
>
> Thank you, Torsten
> _______________________________________________
> Qgis-user mailing list
> Qgis-user at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/qgis-user

-- 
--
Andreas Neumann
Böschacherstrasse 10A
8624 Grüt (Gossau ZH)
Switzerland

------------------------------

Message: 2
Date: Wed, 27 Jul 2011 10:00:27 +0100
From: "Chris Green" <chris.green at ibstv.co.uk>
Subject: RE: [Qgis-user] QGIS -> MySQL -> Mapserver ??
To: "'Saber Razmjooei'" <razmjooeis at faunalia.co.uk>
Cc: qgis-user at lists.osgeo.org
Message-ID: <02a401cc4c3b$a25fa3a0$e71eeae0$@green at ibstv.co.uk>
Content-Type: text/plain; charset="us-ascii"

Hi Saber 

Thanks for the suggestion. When I run ogrinfo -formats I see that MySQL is
included, so that is not the problem.

It seems that the issue is about the way that I created and store the line
data, because I have tried with some point data and I don't have this
problem - I can create, save, and display points with QGIS and then both OGR
and MapServer are OK. But with line data it is different.

I can only assume that QGIS is sending the line data to MySQL in a format
that QGIS recognises when the data is retrieved, but which is not recognised
by OGR / MapServer.

Going to PostGIS would have to be a last resort, I have a lot of effort
invested in MySQL ..

Chris 

From: Saber Razmjooei [mailto:razmjooeis at faunalia.co.uk] 
Sent: 27 July 2011 09:35
To: Chris Green
Cc: qgis-user at lists.osgeo.org
Subject: Re: [Qgis-user] QGIS -> MySQL -> Mapserver ??

Chris

I presume your ogr can handle mysql if you can open it in QGIS. But to
confirm could you run:

ogrinfo --formats

from terminal and check if you have 

-> "MSSQLSpatial" (read/write)

Is your database large? Have you considered using PostGIS?

Cheers
Saber

On 27/07/11 07:45, Chris Green wrote: 

Hi QGIS users

I have a problem getting Mapserver to display vector line features which I
created with QGIS and saved as spatial objects in MySQL...I asked for some
advice on this from the Mapserver forum yesterday but had no responses,
perhaps someone in this forum has some experience to offer?

As explained in the question below, I can create line features in QGIS, save
them in a MySQL table, and recall and display them with QGIS without any
problem.  But the same features do not appear to be recognised by OGRInfo or
by Mapserver. The line features are saved as BLOB data in a MySQL  MyISAM
table in a column which is defined as type 'geometry'. MySQL can create a
spatial index of these features.

The table is accessed by QGIS as a database layer via the 'Add Vector Layer'
dialogue. I am using QGIS 1.7. 

It's not really a QGIS problem, but I spent all day wrestling with this
yesterday but have not solved it.  Any suggestions?

Chris

############################################################################
###     

I'm having some trouble with an OGR connection to a MySQL database. The data
I'm trying to access was created using QGIS as a line layer and saved in a
MySQL table as a BLOB in a geometry column. I can access and properly
display this line data using QGIS, but not so far via Mapserver - nothing is
drawn and I can't see any error.

I am using Mapserver 6.0 and my mapfile is very similar to the example in
theMapserver / MYSQL  documentation:

LAYER

       NAME "testLine" 

       TYPE   LINE

       STATUS  DEFAULT

       CONNECTIONTYPE  OGR

       CONNECTION  "mysql:testDB,user=admin,password=password,port=3306" 

       DATA "SELECT Geometry from testLine"

       CLASS

              STYLE        

                     COLOR  0 0 0

                     WIDTH  2      

              END # style

       END # class

END # layer

If I look at the MySQL table using OGRinfo I see the following:

Layer name: testLine

Geometry: Unknown (any)

Feature Count: 0

Layer SRS WKT: 

(unknown)

FID Coumn = id

Geometry Column = Geometry

The issue seems to be that OGRInfo and therefore MapServer does not
recognise any features in the table, but QGIS using access to the same table
finds and displays the features.

Anyone have any ideas what I am doing wrong?

Chris

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Message: 3
Date: Wed, 27 Jul 2011 10:55:20 +0100
From: Saber <razmjooeis at faunalia.co.uk>
Subject: RE: [Qgis-user] QGIS -> MySQL -> Mapserver ??
To: Chris Green <chris.green at ibstv.co.uk>
Cc: qgis-user at lists.osgeo.org
Message-ID: <05cdp715sy1xrat8ywciguee.1311760349356 at email.android.com>
Content-Type: text/plain; charset=utf-8

As a test, worth converting the mysql vector to shapefile to see if the vector is shown properly.

Also checking webserver logs report for mapsever requests of the MySQL vector might help.

Chris Green <chris.green at ibstv.co.uk> wrote:

>Hi Saber 
>
> 
>
>Thanks for the suggestion. When I run ogrinfo -formats I see that MySQL is
>included, so that is not the problem.
>
>It seems that the issue is about the way that I created and store the line
>data, because I have tried with some point data and I don't have this
>problem - I can create, save, and display points with QGIS and then both OGR
>and MapServer are OK. But with line data it is different.
>
> 
>
>I can only assume that QGIS is sending the line data to MySQL in a format
>that QGIS recognises when the data is retrieved, but which is not recognised
>by OGR / MapServer.
>
> 
>
>Going to PostGIS would have to be a last resort, I have a lot of effort
>invested in MySQL ..
>
> 
>
> 
>
> 
>
>Chris 
>
> 
>
>From: Saber Razmjooei [mailto:razmjooeis at faunalia.co.uk] 
>Sent: 27 July 2011 09:35
>To: Chris Green
>Cc: qgis-user at lists.osgeo.org
>Subject: Re: [Qgis-user] QGIS -> MySQL -> Mapserver ??
>
> 
>
>Chris
>
>I presume your ogr can handle mysql if you can open it in QGIS. But to
>confirm could you run:
>
>ogrinfo --formats
> 
> 
> 
>
>from terminal and check if you have 
>
>-> "MSSQLSpatial" (read/write)
>
>Is your database large? Have you considered using PostGIS?
>
>Cheers
>Saber
>
>
>On 27/07/11 07:45, Chris Green wrote: 
>
> 
> 
>Hi QGIS users
> 
> 
> 
>I have a problem getting Mapserver to display vector line features which I
>created with QGIS and saved as spatial objects in MySQL...I asked for some
>advice on this from the Mapserver forum yesterday but had no responses,
>perhaps someone in this forum has some experience to offer?
> 
> 
> 
>As explained in the question below, I can create line features in QGIS, save
>them in a MySQL table, and recall and display them with QGIS without any
>problem.  But the same features do not appear to be recognised by OGRInfo or
>by Mapserver. The line features are saved as BLOB data in a MySQL  MyISAM
>table in a column which is defined as type 'geometry'. MySQL can create a
>spatial index of these features.
> 
> 
> 
>The table is accessed by QGIS as a database layer via the 'Add Vector Layer'
>dialogue. I am using QGIS 1.7. 
> 
> 
> 
>It's not really a QGIS problem, but I spent all day wrestling with this
>yesterday but have not solved it.  Any suggestions?
> 
> 
> 
> 
> 
> 
> 
>Chris
> 
> 
> 
>############################################################################
>###     
> 
> 
> 
> 
> 
>I'm having some trouble with an OGR connection to a MySQL database. The data
>I'm trying to access was created using QGIS as a line layer and saved in a
>MySQL table as a BLOB in a geometry column. I can access and properly
>display this line data using QGIS, but not so far via Mapserver - nothing is
>drawn and I can't see any error.
> 
> 
> 
>I am using Mapserver 6.0 and my mapfile is very similar to the example in
>theMapserver / MYSQL  documentation:
> 
> 
> 
>LAYER
> 
>       NAME "testLine" 
> 
>       TYPE   LINE
> 
>       STATUS  DEFAULT
> 
>       CONNECTIONTYPE  OGR
> 
>       CONNECTION  "mysql:testDB,user=admin,password=password,port=3306" 
> 
>       DATA "SELECT Geometry from testLine"
> 
>       CLASS
> 
>              STYLE        
> 
>                     COLOR  0 0 0
> 
>                     WIDTH  2      
> 
>              END # style
> 
>       END # class
> 
>END # layer
> 
> 
> 
> 
> 
> 
> 
>If I look at the MySQL table using OGRinfo I see the following:
> 
> 
> 
>Layer name: testLine
> 
>Geometry: Unknown (any)
> 
>Feature Count: 0
> 
>Layer SRS WKT: 
> 
>(unknown)
> 
>FID Coumn = id
> 
>Geometry Column = Geometry
> 
> 
> 
> 
> 
>The issue seems to be that OGRInfo and therefore MapServer does not
>recognise any features in the table, but QGIS using access to the same table
>finds and displays the features.
> 
> 
> 
> 
> 
>Anyone have any ideas what I am doing wrong?
> 
> 
> 
> 
> 
>Chris
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
>_______________________________________________
>Qgis-user mailing list
>Qgis-user at lists.osgeo.org
>http://lists.osgeo.org/mailman/listinfo/qgis-user
>
> 
>

------------------------------

Message: 4
Date: Wed, 27 Jul 2011 14:09:39 +0400
From: Maxim Dubinin <sim at gis-lab.info>
Subject: [Qgis-user] DTclassifier is released
To: qgis-developer at lists.osgeo.org
Cc: qgis-user at lists.osgeo.org
Message-ID: <77239752.20110727140939 at gis-lab.info>
Content-Type: text/plain; charset=us-ascii

Hi all,

To follow up on our demonstration in Lisbon.

We  are happy to release our new plugin for streamlined remote sensing
data    classification    in    QGIS    [0].  Initially the plugin was
developed   to   provide   easy  to  use  tool to monitor forest cover
change, but it can be used to classify any type of targets.

Main features:
-  all-in-one, with this plugin only QGIS is needed for all steps of
classification;
-  decision trees,  the  plugin  is  using  computer  vision library OpenCV to
implement  modern  classification algorithm typically not available in
other software packages (both OS and proprietory);
-   performance,   another   nice  feature  of  OpenCV  is  that it is
very fast;
- multiple input rasters and multiple training layers;

Description, examples and sample data:
EN: http://gis-lab.info/qa/dtclassifier-eng.html
RU: http://gis-lab.info/qa/dtclassifier.html

Right now the windows binaries and source code are available.

---------
Maxim

[0] http://www.nextgis.ru/projects/dtclassifier

------------------------------

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