[GRASS-user] Connecting GRASS to a MySQL database ?

[Thom DeCarlo]

Richard,
Yeah... Merge might not be the right word. I'm importing a lot of files  
downloaded from the USGS site, for example, state boundaries. There are 6  
separate files, but I want them all to go into the same database table/map  
layer. The import vector function always wants to put each import into its  
own table/layer.

Thom

Sent via DROID on Verizon Wireless

-----Original message-----
From: Richard Chirgwin <rchirgwin at ozemail.com.au>
To: Thom DeCarlo <pixelpusher at cox.net>
Cc: grass-user at lists.osgeo.org
Sent: 2010 Sep, Fri, 24 21:46:26 GMT+00:00
Subject: Re: [GRASS-user] Connecting GRASS to a MySQL database?

  It depends on what you mean by "merge".

v.patch is the "official" tool to merge two vectors, but you could use  
v.overlay (option=or).

Richard

On 24/09/10 10:56 PM, Thom DeCarlo wrote:
> Richard,
> Thanks! That was exactly the information I needed.
>
> Now to figure out how to merge layers...
>
> Thom
>
> /Sent via DROID on Verizon Wireless/
>
>
> -----Original message-----
>
>     *From: *Richard Chirgwin <rchirgwin at ozemail.com.au>*
>     To: *grass-user at lists.osgeo.org*
>     Sent: *2010 Sep, Thu, 23 07:20:51 GMT+00:00*
>     Subject: *Re: [GRASS-user] Connecting GRASS to a MySQL database?
>
>     On 23/09/10 5:13 PM, grass-user-request at lists.osgeo.org wrote:
>     > Message: 3
>     > Date: Wed, 22 Sep 2010 16:51:08 -0400 (EDT)
>     > From: PixelPusher
>     > Subject: [GRASS-user] Connecting GRASS to a MySQL database?
>     > To:grass-user at lists.osgeo.org
>     > Message-ID:
>     > Content-Type: text/plain; charset=UTF-8; format=flowed; delsp=no
>     >
>     > Sorry for the n00bish question, but I'm confused by the GRASS
>     on-line
>     > docs.
>     >
>     > I have a MySQL database running on my local computer. Let's say
>     that the
>     > MySQL user name is TRD and he has access to a database called
>     TRD where
>     > I want to store my StateBoundaries table.
>     >
>     > I can start the GRASS (6.4.0) Python interface and select
>     > "Database->Manage Databases->Connect" from the pulldown menu. I
>     am then
>     > faced with the choice of driver, where I select "mysql". But,
>     then it
>     > needs the Database name. This is where I get lost. The string in the
>     > text field says, "$GISDBASE/$LOCATION_NAME/$MAPSET/TRD". I'm not
>     sure
>     > where GRASS is getting the values that substitute for those
>     things that
>     > look like script variables. I guess the "$LOCATION_NAME" and
>     "$MAPSET"
>     > come from the location and mapset that I selected when GRASS
>     started.
>     > But, where is "$GISDBASE" set?
>     >
>     > I also step through the log in process by setting the
>     appropriate user
>     > name and password. I know that I can use this combination to
>     access the
>     > MySQL database through its command line interface.
>     >
>     > The next thing I do is try to test the connection. However, this
>     results
>     > in lots of errors like, "Cannot connect to MySQL, Access denied for
>     > user" and "ERROR: Unable to open database
>     > <$GISDBASE/$LOCATION_NAME/$MAPSET/TRD>". It looks like GRASS is not
>     > using the right username and password and not doing the variable
>     > substitution that I was expecting.
>     >
>     > Can anoyone give me some hints on how to get this thing started?
>     >
>     > Thanks!
>     > Thom
>     Thom,
>
>     Having taught a few people how to use Grass-GIS, I can say that
>     database parameters confuse a great many of them!
>
>     The parameters you see are for the default dbf driver (Grass-GIS
>     uses this driver as the default for any new mapset). For MySQL,
>     you provide the database location, and also login.
>
>     So where you see the $GISDBASE/$LOCATION_NAME/$MAPSET/dbf/ string,
>     you want:
>     database=host=,dbname=TRD
>
>     But you'll also have to login. Eg (command line):
>
>     db.login user=TRD password="somepassword"
>
>     (the inverted commas are needed at the command line but not using
>     the GUI)
>
>     Notes:
>
>     1. From now on, every map you make in this particular mapset will
>     use the MySQL database as its default connection. Don't try to mix
>     different database drivers within a mapset - you'll get a headache!
>
>     2. Database parameters are stored only within the mapset you're
>     using. If you want to connect a different mapset to MySQL, you
>     have to set its connection.
>
>     Richard Chirgwin
>     _______________________________________________
>     grass-user mailing list
>     grass-user at lists.osgeo.org
>     http://lists.osgeo.org/mailman/listinfo/grass-user
>



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