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How do I identify which features have NULL attributes in the attribute table of a shapefile?

When i try [field]= 'NULL' it selects the features with value = 0 (see picture)

example

0
61

Have you tried replacing the "=" with "is"? I don't have QGIS in front of me, but that is pretty common database select syntax for working with NULL values.

pedonal is NULL
1

I beat my brains about this one. The field name is "ASSETID", it is either a value or NULL. But actually the field was a text field (KML). I tried..

"ASSETID" ISNULL, "ASSETID" IS NULL, ISNULL("ASSETID"), "ASSETID" = ""  NOTHING WORKED!

However

"ASSETID" = '', "ASSETID" IN ('') did work also for search "ASSETID" in ('2251', '4321' etc)

Archaic but workable.

-2

This video instructs you how to update these selected Null values from another shapefile (layer). https://youtu.be/O2hkvJjR2_s

3
  • 6
    This video may answer the question but it can get offline someday. So it would be useful if you could include a short summary in your answer. – MrXsquared Aug 23 '19 at 23:28
  • 2
    Link-only answers are often deleted as non-answer Answers, because the information is not present in the Answer itself. – Vince Aug 24 '19 at 23:15
  • The video is unavailable. – Kübra Sep 8 '20 at 12:49
-5

Try:

Pedonal = ''

  • that should work!
2
  • that works for text fields...i'm using numerical fields, and that selects values = to 0 – vascobnunes Oct 24 '11 at 15:48
  • 11
    @Darren Cope, NULL is different than "" – artwork21 Oct 25 '11 at 14:25

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