[Qgis-user] QGIS -> MySQL -> Mapserver ??

[Chris Green]

Saber

Ogrinfo -summary on the MySQL table as saved by QGIS says:

Layer name:	 geom_test
Geometry: Unknown (any)
Feature Count: 0
Layer SRS WKT: 
(unknown)
FID Column = id
Geometry Column = Geometry


Ogrinfo -summary on the table after running SELECT AsWKB(Geometry) says:

Layer name:	 geom_test_converted
Geometry: Unknown (any)
Feature Count: 34
Layer SRS WKT: 
(unknown)
FID Column = id
Geometry Column = Geometry
 
There is no projection in the layer, QGIS seems to assume that it is lat/lon
and then reprojects it to 900913, which is what I am using overall.

Maybe the lack of projection in the data is confusing OGR....but I'm not
sure that if I apply projection to the layer via QGIS, it will get saved as
part of the MySQL data??

   
Chris



-----Original Message-----
From: Saber Razmjooei [mailto:razmjooeis at faunalia.co.uk] 
Sent: 27 July 2011 14:04
To: Chris Green
Cc: qgis-user at lists.osgeo.org
Subject: RE: [Qgis-user] QGIS -> MySQL -> Mapserver ??

What does ogrinfo -al say about your geometry? Are those numbers located
in the right place? Just to make sure your layer projection is set
properly.


> Hi Saber
>
> I tried that, and the when the MySQL data is saved as an ESRI shapefile
> the shapefile opens correctly.
>
> I have been experimenting with converting the MySQL BLOB data. For example
> if I try
>
> SELECT AsText(Geometry) I get a line string which looks OK and could be
> used to create a line feature in MapServer using PHP Mapscript. Then when
> I try:
>
> SELECT AsWKB(Geometry) I get a new set of BLOBs which can be recognised by
> OGRinfo as features (progress!!!) but still not displayed by MapServer.
>
> My conclusion is that QGIS is using some internal format to store MySQL
> linestrings which is not properly understood by OGR.
>
> Any idea where I could find out any more on this?
>
>
> Chris
>
>
>
> -----Original Message-----
> From: Saber [mailto:razmjooeis at faunalia.co.uk]
> Sent: 27 July 2011 10:55
> To: Chris Green
> Cc: qgis-user at lists.osgeo.org
> Subject: RE: [Qgis-user] QGIS -> MySQL -> Mapserver ??
>
> 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
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
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>>Qgis-user at lists.osgeo.org
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>>
>>
>>
>
>
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