[Gvsig_english] JOIN

[Kai-Christian Bruhn]

Step 1 refers to one of my initial questions: How to start editing of 
imported tables?

Benjamin Ducke schrieb:
> CSV import is currently too limited to be really useful, I think.
> For the time being, the preferred way to import simple tables is
> via DBF.
> 
> However, you can make data imported from a CSV file more useful
> in gvSIG: use the Field Calculator.
> 
> E.g.to convert a key field for joins from text to numeric:
> 
> 1. Start editing the imported table
> 
> 2. Create a new, numeric field for the key
> 
> 3. Use the "toNumber" function in the field calculator to
> create numeric values from the original text type key field
> 
> 4. delete the old field
> 
> Again, an extra step, but at least can be done in gvSIG itself.
> 
> Ben
> 
> Kai-Christian Bruhn wrote:
>> Hi Ben,
>>
>> thanks a lot!
>>
>> Good to know about the limitations of the csv-import. So what is it 
>> actually good for? Comma Separated Values as strings in a GIS?
>>
>> The dbf-import works fine. I'm preparing some manuals for basic 
>> editing and would have loved to omit another step (csv2dbf) before 
>> joining in gvSIG.
>>
>> Anyway, I conclude that csv-import is dubious and that there is no 
>> gvSIG-internal solution for editing plain table data. Agree?
>>
>> Kai
>>
>> Benjamin Ducke schrieb:
>>> The CSV import in 1.1.2 is weak in that it imports all table fields
>>> as type "text". Unfortunately, you cannot use a field of that type
>>> as a key field in a join operation. The key field needs to be type
>>> "integer". Instead of joining data from a CSV file, save your data
>>> as DBF (Open Office Calc does that just fine, but so should Excel --
>>> with some added quirks, I suspect). Make sure to set the field type
>>> to numeric with zero decimal places in your spreadsheet.
>>> Then join the DBF table to your Shapefile.
>>>
>>> Ben
>>>
>>> Kai-Christian Bruhn wrote:
>>>> Dear list,
>>>>
>>>> this and the related thread starts to convince me that I'm the 
>>>> problem in joining attribute tables and not gvSIG. Nevertheless, I 
>>>> tried several times to join an imported csv-file with a 
>>>> shape-dbf-file - and failed. So please dwell a little more on that 
>>>> subject.
>>>> The details:
>>>> gvSIG OA Digital Edition with Java 1.6.0_07 on XP Professional
>>>> A shapefile with 2D-points, an integer attribute fo_id and more string
>>>> type attribute fields.
>>>> A csv-file like this:
>>>> fo_id;type
>>>> 1;burial
>>>> 2;single finding
>>>> 3;burial
>>>> 4;pit
>>>> etc...
>>>> Both tables are in the project manager table view but join wouldn't
>>>> work. I guess the problem emerges already during the import
>>>> of the csv, as it seems to take the fo_id as a string type, not as
>>>> integer. So when trying to join fo_id from the shape-dbf the 
>>>> dropdown of
>>>> the last dialogue where to choose the field from the csv for joining is
>>>> empty. For testing I went the other way around, calling the imported 
>>>> csv
>>>> first and the shape-dbf second. The last dropdown then offers only the
>>>> string-type fields from the attribute table of the shape-dbf.
>>>>
>>>> Is there any way to edit plain table data in gvsig?
>>>> Is there a way to assign types to imported table fields?
>>>> Does it need a csvt-file as in ogr2ogr csv-handling to assign types 
>>>> to data?
>>>>
>>>> Or am I simply incapable?
>>>>
>>>> Cheers
>>>>
>>>> Kai
>>>>
>>>> John Ladd schrieb:
>>>>> With a little help from Benjamin Ducke I determined what I was doing
>>>>> wrong re the JOIN function.  I was not paying attention to the buttons
>>>>> on the first of the four screens and was then making wrong assumptions
>>>>> re buttons on successive screens where the buttons were not clearly
>>>>> labelled.  In hindsight this sounds just careless on my part, but it
>>>>> underscores the problems faced by new users.  Somewhere long ago I
>>>>> read that in the process of developing software for third party use
>>>>> ~20% of the effort is generating software that works for the developer
>>>>> and ~80% of the effort is packaging the software so that the third
>>>>> party can use it.
>>>>>
>>>>> thank you for your patience.
>>>>>
>>>>
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>>>>
>>>>
>>>
>>>
>>
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