[Qgis-user] Newbie Questions
tech_dev at wildintellect.com
Wed Sep 29 19:20:44 EDT 2010
On 09/28/2010 10:46 AM, Michael Lapson wrote:
> Hi Everyone,
> I am an experienced user of ArcGIS, starting over with QGIS. I frequently
> use MS Excel to create a table of attributes, then load into GIS and join
> these attributes onto an existing shapefile.
> 1. I tried doing this with Join Attributes and selecting the CSV file.
> However I found that when QGIS reads in the CSV file, it casts all of the
> columns as Text, so I couldn't use the numerical values. I notice the Join
> Attributes from CSV feature is new in QGIS 1.5.0. Maybe there is a bug?
> 2. Eventually I will want to put my data into a database. I notice I can
> choose between SpatiaLite and PostGIS. Which is easier to use? Is there a
> performance difference?
> 3. In ArcMap, I frequently used the capability to vary the thickness of line
> features according to a value in the attribute table. I notice that this
> capability is available in QGIS only for points ("drawing by field") but not
> for line features. Is there another way to accomplish variable thickness
> lines in QGIS? If not, is "drawing by field" for line features under
> I would appreciate any help you can offer as I am getting started with QGIS.
As an alternative to the other thread, I would suggest you import your
spatial data and table into your database 1st and do the join in the
database. It's really easy to do in a database with a Create Table query
and a JOIN operation.
Spatialite is a single file database that works quite well for one user.
Postgis requires running a service and configuring authentication and
some other parameters but theoretically scales much larger than sqlite.
I would recommend starting with spatialite and moving to postgis when
you know what you need and want to do.
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