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

[Chris Green]

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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