Bug report #13800

Field names that are numbers should be quoted when converting renderers

Added by Guillaume CORNU about 7 years ago. Updated almost 4 years ago.

Affected QGIS version:2.12.0 Regression?:No
Operating System: Easy fix?:No
Pull Request or Patch supplied:No Resolution:end of life
Crashes QGIS or corrupts data:No Copied to github as #:21825


When converting from a categorized or graduated renderer to
a rule-based renderer, attribute name that happen to be numbers
should be quoted.
This is not a blocking bug but is very confusing and error prone.
A workaround is to manually change each rule quoting attributes

for example
  • GIVEN a layer with numeric field/column/attribute named "2013"
  • BUILD a graduated renderer upon this field/column/attribute and classify values
  • CONVERT to a rule-based renderer
  • You'll get rules like '2013 > 10 AND 2013 <= 25'
  • It should be ' "2013" > 10 AND "2013" <= 25'
I tracked the origin of this default to convertFromRenderer functions in renderers class
QgsRuleBasedRendererV2* QgsRuleBasedRendererV2::convertFromRenderer( const QgsFeatureRendererV2* renderer )

where we can find lines like
expression = graduatedRenderer->classAttribute() + " >= " + QString::number( range.lowerValue(), 'f' ) + " AND " + \\
             graduatedRenderer->classAttribute() + " <= " + QString::number( range.upperValue(), 'f' );

I unfortunately cannot provide a patch but can suggest to
  • conditionnaly quote classAttribute()
  • or easer introduce a new function safeClassAttribute() that automatically quote the attribute and use it whenever needed

Associated revisions

Revision cb5f7485
Added by Matthias Kuhn about 7 years ago

Quote field names when converting renderers

Fix #13800


#1 Updated by Anonymous about 7 years ago

  • Status changed from Open to Closed

#2 Updated by Guillaume CORNU about 7 years ago

  • Status changed from Closed to Reopened

Thank you for the quick update but it partially solve the problem.
classAttribute() appears in several places in this function and the
change should be also done on those places.
I apologize if the issue was not clear enough.

#3 Updated by Giovanni Manghi almost 6 years ago

  • Easy fix? set to No
  • Regression? set to No

#4 Updated by Giovanni Manghi almost 4 years ago

  • Resolution set to end of life
  • Status changed from Reopened to Closed

End of life notice: QGIS 2.18 LTR


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