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How to extend attribute table field size from 255 char

October 12 2011 | 4 comments
Categories: Labeling


I have a polygon layer, and I joined an Excel spreadsheet to this. I've checked the success of the join, and I saw that the joined field sizes are reduced to 255 characters. Excel can store 32k chars in a field, but I only have 300-400 chars. I need to query datas in ArcGIS, and the 255 character limit isn't good for me.

I tested an another method: I created an FGDB, and made a relationship class between the imported excel spreadsheet and the polygon layer. My problem is that, the fields are reduced again, showing only 255 chars.

Any ideas?

Mapping Center Answer:

You can create text fields greater than 255 characters using file geodatabases. First, create a new file geodatabase then create a new feature class. Add a text field as part of the creation of the new feature class and specify the length of text strings should be 400 (or whatever the maximum is that you require). Then, using your original layer, convert labels to annotation and choose to append them to an existing feature class (the one created above).  Export the attribute table of the feature class and you can then copy the labels from your spreadsheet into the text field of your attribute table in Excel, save the resulting table and then Join back to the feature class.

problem posted by JONATHAN SWARTZ on Oct 25 2011 6:58AM

Thanks for the fast reply. I don't understand all the steps.
1. Create a new feature class - you mean annotation?
ArcGIS can't append annotation to a polygon or other feature class. I made an annotation FC, and the source layers annotation is appended to this annotation class.
2, How can I export the attribute table?
I don't know why I need to create anno, append, export, copy, join, because there is an option in FGDB, that if I create a feature class (f.e. a polygon) I can create a text field, length 1000 char, and join the Excel spreadsheet. This is very simple option, but if the attribute table is open, the joined field named "blob". The process, what you wrote above is a bit confused me. Can you tell me more about the process?
alternative posted by Kenneth Field on Oct 25 2011 9:33AM
An alternative process is:
Export your original layer as a polygon feature class in a file geodatabase
Create a new text field of 400 characters
Add your Excel spreadsheet to ArcMap
Perform an attribute join
Use the Field Calculator to copy the text into the empty text field.
You can then un-join the tables.
alternative method fail posted by JONATHAN SWARTZ on Oct 26 2011 3:16AM
Like I wrote, I've tested, the join command between a feature class from an FGDB and an Excel spreadsheet.

The problem is
- I added the feature class
- I added an Excel table
- I joined the Excel table to the feature class
- I opened the attribute table and with field calculator copied the source field to the destination field

The source field contains in every record 100-600 characters; the destination field's long is 800 characters.
- After the copy I checked the results: only 255 chars copied (and only 255 char displayed in the joined fields).

The cutted 255 character-long data is copied into new field. It has failed.

(Here is an example: Sír, szarmata, forrás: Megel?z? és próbafeltárás dokumentációja, Kukutyin123, Pork Center, 2008.; Veréb, szarmata, forrás: ua.; Épület, szarmata, forrás: ua.; Kemenec általában, szarmata, forrás: ua.; Telep általában, szarmata, forrás: ua.; Sír, szarmata,?????º)

This unidentified characters are at the point of the cutting. The other parts of the strings are lost, can't display, and can't copy to the bigger field.

Any other working option?
tech support posted by Kenneth Field on Oct 26 2011 8:40AM
At this stage you probably need to contact Esri Technical Support (through your usual route) to see if they can ascertain precisely the reasons why you don't seem able to use text fields greater than 254 characters. Hopefully they will be able to resolve the issue for you.

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