[postgis-users] QGIS - PostGIS - ArcGIS Interaction

[James David Smith]

Dear Cristian & David,

Thanks alot for your responses.

Cristian - I don't have money to buy additional software
unfortunately. With regard to 'view' I actually don't know what this
is. I'm a bit of a beginner. I wonder if I made a 'view' whether I
could then query that view with QGIS. Something for me to look into...

David - That looks like a good idea... but when adding data to QGIS
you can only select the whole table (I think) and then you manually
enter the 'WHERE' clause in a dialog box. I guess I could run the
query you suggest in PostgreSQL and save it into another table... and
then link QGIS to the new table. Though it all starts to get a bit
convoluted if I have to do that every time I want to look at some data
in QGIS...

Cheers

James



On 15 June 2011 19:16, David Fawcett <david.fawcett at gmail.com> wrote:
> This is what is really cool about using a database to store your data...
>
> Change your query to:
>
> SELECT mycol1,
>             mycol2,
>             date_time_of_arrival as dt_arrive,
>             date_time_of_departure as dt_depart,
>              the_geom
> FROM incidents
> WHERE urgency = 'Immediate'
> AND date_time_of_arrival - date_time_unit_assigned > '00:12:00'
>
> Note: you will need to specify the names of the columns that you are
> interested in.
>
>
> On Wed, Jun 15, 2011 at 12:58 PM, James David Smith
> <james.david.smith at gmail.com> wrote:
>> Dear all,
>>
>> I appreciate that this is more of a QGIS query, but I think that the
>> route of the problem might be in PostGIS, so... I have opened QGIS and
>> ran the query on my PostGIS table as below:
>>
>> SELECT * FROM incidents
>> WHERE urgency = 'Immediate'
>> AND date_time_of_arrival - date_time_unit_assigned > '00:12:00'
>>
>> This gives me 33 points in QGIS. Great. I would now however like to
>> save this as a ShapeFile for use in ArcGIS with which I am more
>> familiar, but when I try to SAVE AS from QGIS I am given the following
>> error....
>>
>> Export to vector file failed.
>> Error: trimming attribute name 'date_time_of_arrival' to ten
>> significant characters produces duplicate column name.
>>
>> I am guessing that the problem here is that ESRI shapefiles can only
>> deal with column names that are ten characters long...? And that as I
>> also have a column called 'date_time_of_departure', when QGIS trims
>> this column it ends up with two columns called the same thing?  Is
>> there a way around this? I realise I could rename the column in QGIS,
>> but I actually have around 45 columns in the table and this problem
>> will occur with about 15 pairs of them I think. I guess there is no
>> simple answer... but thought I'd ask.
>>
>> Cheers
>>
>> James
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