I'm having a problem with QGIS. I'm trying to create a new column in the attribute table for a shapefile. The numbers in the fourth column (see screenshots) are currently strings, so I want to convert them into real numbers. This seems to work just fine until I save my edits. Then all the values in the new column become null.

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It looks like a couple of other people have had this problem (here and here) but they seemed to solve the problem by expanding the width of the output field (from 10 to 20). I tried that, and it didn't make a difference.

Can anyone help?

  • Did you try to create the field first, then "update existing field" in the field calculator ? – radouxju Jan 7 '14 at 6:42
  • 1
    I think that the NULL values appear only temporarily. If you save edits, close and reopen the attribute table, the values should be OK. Also, consider upgrading to version 2.0. This bug is fixed now. – Micha Jan 7 '14 at 8:27
  • Oh, it looks like you're right! Thank you. Will update to the next version too. – Restiva Jan 7 '14 at 15:41
  • I'm having this problem and I'm on version 3.4.6 – user32882 Apr 21 at 12:07
  • And I'm having it with 3.6... – Unrelated Jul 25 at 22:32

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