Merge pull request #7064 from anitagraser/patch-1

[FEATURE] Create PostGISExecuteAndLoadSQL.py

python/plugins/processing/algs/help/qgis.yaml

@@ -356,6 +356,9 @@ qgis:spatialiteexecutesql: >
 qgis:postgisexecutesql: >
   This algorithm performs a SQL database query on a PostGIS database connected to QGIS.
 
+qgis:postgisexecuteandloadsql: >
+  This algorithm performs a SQL database query on a PostGIS database connected to QGIS and loads the query results as a new layer.
+
 qgis:randomextract: >
   This algorithm takes a vector layer and generates a new one that contains only a subset of the features in the input layer.
 

python/plugins/processing/algs/qgis/PostGISExecuteAndLoadSQL.py

@@ -0,0 +1,117 @@
+# -*- coding: utf-8 -*-
+
+"""
+***************************************************************************
+    PostGISExecuteAndLoadSQL.py
+    ---------------------
+    Date                 : May 2018
+    Copyright            : (C) 2018 by Anita Graser
+    Email                : anitagraser at gmx dot at
+    ---------------------
+    based on PostGISExecuteSQL.py by  Victor Olaya and Carterix Geomatics
+***************************************************************************
+*                                                                         *
+*   This program is free software; you can redistribute it and/or modify  *
+*   it under the terms of the GNU General Public License as published by  *
+*   the Free Software Foundation; either version 2 of the License, or     *
+*   (at your option) any later version.                                   *
+*                                                                         *
+***************************************************************************
+"""
+
+__author__ = 'Anita Graser'
+__date__ = 'May 2018'
+__copyright__ = '(C) 2018, Anita Graser'
+
+# This will get replaced with a git SHA1 when you do a git archive
+
+__revision__ = '$Format:%H$'
+
+from qgis.core import (Qgis,
+                       QgsProcessingException,
+                       QgsProcessingParameterString,
+                       QgsApplication,
+                       QgsVectorLayer,
+                       QgsProject,
+                       QgsProcessing,
+                       QgsProcessingException,
+                       QgsProcessingOutputVectorLayer,
+                       QgsProcessingContext,
+                       QgsProcessingFeedback)
+from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
+from processing.tools import postgis
+
+
+class PostGISExecuteAndLoadSQL(QgisAlgorithm):
+
+    DATABASE = 'DATABASE'
+    SQL = 'SQL'
+    OUTPUT = 'OUTPUT'
+    ID_FIELD = 'ID_FIELD'
+    GEOMETRY_FIELD = 'GEOMETRY_FIELD'
+
+    def group(self):
+        return self.tr('Database')
+
+    def groupId(self):
+        return 'database'
+
+    def __init__(self):
+        super().__init__()
+
+    def initAlgorithm(self, config=None):
+        db_param = QgsProcessingParameterString(
+            self.DATABASE,
+            self.tr('Database (connection name)'))
+        db_param.setMetadata({
+            'widget_wrapper': {
+                'class': 'processing.gui.wrappers_postgis.ConnectionWidgetWrapper'}})
+        self.addParameter(db_param)
+        self.addParameter(QgsProcessingParameterString(
+            self.SQL,
+            self.tr('SQL query'),
+            multiLine=True))
+        self.addParameter(QgsProcessingParameterString(
+            self.ID_FIELD,
+            self.tr('Unique ID field name'),
+            defaultValue='id'))
+        self.addParameter(QgsProcessingParameterString(
+            self.GEOMETRY_FIELD,
+            self.tr('Geometry field name'),
+            defaultValue='geom',
+            optional=True))
+        self.addOutput(QgsProcessingOutputVectorLayer(
+            self.OUTPUT,
+            self.tr("Output layer"),
+            QgsProcessing.TypeVectorAnyGeometry))
+
+    def name(self):
+        return 'postgisexecuteandloadsql'
+
+    def displayName(self):
+        return self.tr('PostGIS execute and load SQL')
+
+    def processAlgorithm(self, parameters, context, feedback):
+        connection = self.parameterAsString(parameters, self.DATABASE, context)
+        id_field = self.parameterAsString(parameters, self.ID_FIELD, context)
+        geom_field = self.parameterAsString(
+            parameters, self.GEOMETRY_FIELD, context)
+        uri = postgis.uri_from_name(connection)
+        sql = self.parameterAsString(parameters, self.SQL, context)
+        sql = sql.replace('\n', ' ')
+        uri.setDataSource("", "(" + sql + ")", geom_field, "", id_field)
+
+        vlayer = QgsVectorLayer(uri.uri(), "layername", "postgres")
+
+        if not vlayer.isValid():
+            raise QgsProcessingException(self.tr("""This layer is invalid!
+                Please check the PostGIS log for error messages."""))
+
+        context.temporaryLayerStore().addMapLayer(vlayer)
+        context.addLayerToLoadOnCompletion(
+            vlayer.id(),
+            QgsProcessingContext.LayerDetails('SQL layer',
+                                              context.project(),
+                                              self.OUTPUT))
+
+        return {self.OUTPUT: vlayer.id()}

python/plugins/processing/algs/qgis/QgisAlgorithmProvider.py

@@ -101,6 +101,7 @@
 from .Polygonize import Polygonize
 from .PolygonsToLines import PolygonsToLines
 from .PostGISExecuteSQL import PostGISExecuteSQL
+from .PostGISExecuteAndLoadSQL import PostGISExecuteAndLoadSQL
 from .RandomExtract import RandomExtract
 from .RandomExtractWithinSubsets import RandomExtractWithinSubsets
 from .RandomPointsAlongLines import RandomPointsAlongLines
@@ -216,6 +217,7 @@ def getAlgs(self):
                 Polygonize(),
                 PolygonsToLines(),
                 PostGISExecuteSQL(),
+                PostGISExecuteAndLoadSQL(),
                 RandomExtract(),
                 RandomExtractWithinSubsets(),
                 RandomPointsAlongLines(),