[DBManager] Allow to load a layer without primary key

Author: Hugo Mercier

python/plugins/db_manager/db_plugins/plugin.py

@@ -208,9 +208,24 @@ def sqlResultModel(self, sql, parent):
 
         return SqlResultModel(self, sql, parent)
 
+    def uniqueIdFunction(self):
+        """Return a SQL function used to generate a unique id for rows of a query"""
+        # may be overloaded by derived classes
+        return "row_number() over ()"
+
     def toSqlLayer(self, sql, geomCol, uniqueCol, layerName="QueryLayer", layerType=None, avoidSelectById=False):
         from qgis.core import QgsMapLayer, QgsVectorLayer, QgsRasterLayer
 
+        if uniqueCol is None:
+            if hasattr(self, 'uniqueIdFunction'):
+                uniqueFct = self.uniqueIdFunction()
+                if uniqueFct is not None:
+                    q = 1
+                    while "_subq_%d_" % q in sql:
+                        q += 1
+                    sql = "SELECT %s AS _uid_,* FROM (%s) AS _subq_%d_" % (uniqueFct, sql, q)
+                    uniqueCol = "_uid_"
+
         uri = self.uri()
         uri.setDataSource("", u"(%s\n)" % sql, geomCol, "", uniqueCol)
         if avoidSelectById:

python/plugins/db_manager/db_plugins/spatialite/plugin.py

@@ -144,6 +144,8 @@ def runAction(self, action):
 
         return Database.runAction(self, action)
 
+    def uniqueIdFunction(self):
+        return None
 
 class SLTable(Table):
     def __init__(self, row, db, schema=None):

python/plugins/db_manager/dlg_sql_window.py

@@ -178,18 +178,17 @@ def executeSql(self):
         QApplication.restoreOverrideCursor()
 
     def loadSqlLayer(self):
-        uniqueFieldName = self.uniqueCombo.currentText()
+        hasUniqueField = self.uniqueColumnCheck.checkState() == Qt.Checked
+        if hasUniqueField:
+            uniqueFieldName = self.uniqueCombo.currentText()
+        else:
+            uniqueFieldName = None
         hasGeomCol = self.hasGeometryCol.checkState() == Qt.Checked
         if hasGeomCol:
             geomFieldName = self.geomCombo.currentText()
         else:
             geomFieldName = None
 
-        if (hasGeomCol and geomFieldName == "") or uniqueFieldName == "":
-            QMessageBox.warning(self, self.tr("DB Manager"), self.tr(
-                "You must fill the required fields: \ngeometry column - column with unique integer values"))
-            return
-
         query = self.editSql.text()
         if query == "":
             return

python/plugins/db_manager/ui/DlgSqlWindow.ui

@@ -6,7 +6,7 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>747</width>
+    <width>800</width>
     <height>525</height>
    </rect>
   </property>
@@ -181,7 +181,7 @@
          <item row="0" column="0">
           <layout class="QHBoxLayout" name="horizontalLayout_6">
            <item>
-            <widget class="QLabel" name="label_4">
+            <widget class="QCheckBox" name="uniqueColumnCheck">
              <property name="text">
               <string>Column with unique 
 integer values</string>
@@ -190,6 +190,9 @@ integer values</string>
            </item>
            <item>
             <widget class="QComboBox" name="uniqueCombo">
+             <property name="enabled">
+              <bool>false</bool>
+             </property>
              <property name="sizePolicy">
               <sizepolicy hsizetype="Expanding" vsizetype="Fixed">
                <horstretch>0</horstretch>
@@ -403,5 +406,21 @@ columns</string>
     </hint>
    </hints>
   </connection>
+  <connection>
+   <sender>uniqueColumnCheck</sender>
+   <signal>toggled(bool)</signal>
+   <receiver>uniqueCombo</receiver>
+   <slot>setEnabled(bool)</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>109</x>
+     <y>385</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>274</x>
+     <y>385</y>
+    </hint>
+   </hints>
+  </connection>
  </connections>
 </ui>