[processing][gdal] Dissolve field name should be optional

nyalldawson · nyalldawson · commit ea2c16dd6431 · 2018-09-25T11:14:33.000+10:00
diff --git a/python/plugins/processing/algs/gdal/Dissolve.py b/python/plugins/processing/algs/gdal/Dissolve.py
@@ -25,8 +25,7 @@
 
 __revision__ = '$Format:%H$'
 
-from qgis.core import (QgsProcessing,
-                       QgsProcessingException,
+from qgis.core import (QgsProcessingException,
                        QgsProcessingParameterDefinition,
                        QgsProcessingParameterFeatureSource,
                        QgsProcessingParameterField,
@@ -61,7 +60,7 @@ def initAlgorithm(self, config=None):
                                                       self.tr('Dissolve field'),
                                                       None,
                                                       self.INPUT,
-                                                      QgsProcessingParameterField.Any))
+                                                      QgsProcessingParameterField.Any, optional=True))
         self.addParameter(QgsProcessingParameterString(self.GEOMETRY,
                                                        self.tr('Geometry column name'),
                                                        defaultValue='geometry'))
@@ -85,7 +84,7 @@ def initAlgorithm(self, config=None):
                                                   self.tr('Numeric attribute to calculate statistics on'),
                                                   None,
                                                   self.INPUT,
-                                                  QgsProcessingParameterField.Any,
+                                                  QgsProcessingParameterField.Numeric,
                                                   optional=True))
         params.append(QgsProcessingParameterString(self.OPTIONS,
                                                    self.tr('Additional creation options'),
@@ -160,15 +159,17 @@ def getConsoleCommands(self, parameters, context, feedback, executing=True):
 
         params = ','.join(tokens)
         if params:
-            if self.parameterAsBool(parameters, self.KEEP_ATTRIBUTES, context):
-                sql = "SELECT ST_Union({}) AS {}{}, {} FROM '{}' GROUP BY {}".format(geometry, geometry, other_fields, params, layerName, fieldName)
-            else:
-                sql = "SELECT ST_Union({}) AS {}, {}, {} FROM '{}' GROUP BY {}".format(geometry, geometry, fieldName, params, layerName, fieldName)
+            params = ', ' + params
+
+        group_by = ''
+        if fieldName:
+            group_by = ' GROUP BY {}'.format(fieldName)
+
+        if self.parameterAsBool(parameters, self.KEEP_ATTRIBUTES, context):
+            sql = "SELECT ST_Union({}) AS {}{}{} FROM '{}'{}".format(geometry, geometry, other_fields, params, layerName, group_by)
         else:
-            if self.parameterAsBool(parameters, self.KEEP_ATTRIBUTES, context):
-                sql = "SELECT ST_Union({}) AS {}{} FROM '{}' GROUP BY {}".format(geometry, geometry, other_fields, layerName, fieldName)
-            else:
-                sql = "SELECT ST_Union({}) AS {}, {} FROM '{}' GROUP BY {}".format(geometry, geometry, fieldName, layerName, fieldName)
+            sql = "SELECT ST_Union({}) AS {}{}{} FROM '{}'{}".format(geometry, geometry, ', ' + fieldName if fieldName else '',
+                                                                     params, layerName, group_by)
 
         arguments.append(sql)
 
diff --git a/python/plugins/processing/tests/GdalAlgorithmsTest.py b/python/plugins/processing/tests/GdalAlgorithmsTest.py
@@ -621,6 +621,15 @@ def testDissolve(self):
         alg.initAlgorithm()
 
         with tempfile.TemporaryDirectory() as outdir:
+            self.assertEqual(
+                alg.getConsoleCommands({'INPUT': source,
+                                        'OUTPUT': outdir + '/check.shp'}, context, feedback),
+                ['ogr2ogr',
+                 outdir + '/check.shp ' +
+                 source + ' ' +
+                 '-dialect sqlite -sql "SELECT ST_Union(geometry) AS geometry FROM \'polys2\'" ' +
+                 '-f "ESRI Shapefile"'])
+
             self.assertEqual(
                 alg.getConsoleCommands({'INPUT': source,
                                         'FIELD': 'my_field',
@@ -652,6 +661,27 @@ def testDissolve(self):
                  '-dialect sqlite -sql "SELECT ST_Union(the_geom) AS the_geom, my_field FROM \'polys2\' ' +
                  'GROUP BY my_field" -f "ESRI Shapefile"'])
 
+            self.assertEqual(
+                alg.getConsoleCommands({'INPUT': source,
+                                        'FIELD': 'my_field',
+                                        'KEEP_ATTRIBUTES': False,
+                                        'OUTPUT': outdir + '/check.shp'}, context, feedback),
+                ['ogr2ogr',
+                 outdir + '/check.shp ' +
+                 source + ' ' +
+                 '-dialect sqlite -sql "SELECT ST_Union(geometry) AS geometry, my_field FROM \'polys2\' ' +
+                 'GROUP BY my_field" -f "ESRI Shapefile"'])
+
+            self.assertEqual(
+                alg.getConsoleCommands({'INPUT': source,
+                                        'KEEP_ATTRIBUTES': False,
+                                        'OUTPUT': outdir + '/check.shp'}, context, feedback),
+                ['ogr2ogr',
+                 outdir + '/check.shp ' +
+                 source + ' ' +
+                 '-dialect sqlite -sql "SELECT ST_Union(geometry) AS geometry FROM \'polys2\'" ' +
+                 '-f "ESRI Shapefile"'])
+
             self.assertEqual(
                 alg.getConsoleCommands({'INPUT': source,
                                         'FIELD': 'my_field',
