Merge pull request #38641 from domi4484/mssqldefaultvalues

Implemented method QgsMssqlProvider::defaultValue
qgis · Sep 17, 2020 · 9e654ca · 9e654ca
2 parents 44fb4f5 + 8609a72
commit 9e654ca
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Showing 3 changed files with 62 additions and 2 deletions.
diff --git a/src/providers/mssql/qgsmssqlprovider.cpp b/src/providers/mssql/qgsmssqlprovider.cpp
@@ -544,7 +544,52 @@ QString QgsMssqlProvider::quotedIdentifier( const QString &value )
 
 QString QgsMssqlProvider::defaultValueClause( int fieldId ) const
 {
-  return mDefaultValues.value( fieldId, QString() );
+  const QString defVal = mDefaultValues.value( fieldId, QString() );
+
+  if ( defVal.isEmpty() )
+    return QString();
+
+  // NOTE: If EvaluateDefaultValues is activated it is impossible to get the defaultValueClause.
+  //       This also apply to QgsPostgresProvider::defaultValueClause.
+  if ( !providerProperty( EvaluateDefaultValues, false ).toBool() )
+    return defVal;
+
+  return QString();
+}
+
+QVariant QgsMssqlProvider::defaultValue( int fieldId ) const
+{
+  const QString defVal = mDefaultValues.value( fieldId, QString() );
+
+  if ( defVal.isEmpty() )
+    return QVariant();
+
+  if ( !providerProperty( EvaluateDefaultValues, false ).toBool() )
+    return QVariant();
+
+  QString sql = QStringLiteral( "select %1" )
+                .arg( defVal );
+
+  QSqlQuery query = createQuery();
+  query.setForwardOnly( true );
+
+  if ( !query.exec( sql ) )
+  {
+    const QString errorMessage( tr( "Could not execute query: %1" ).arg( query.lastError().text() ) );
+    QgsDebugMsg( errorMessage );
+    pushError( errorMessage );
+    return QVariant();
+  }
+
+  if ( !query.next() )
+  {
+    const QString errorMessage( tr( "Could not fetch next query value: %1" ).arg( query.lastError().text() ) );
+    QgsDebugMsg( errorMessage );
+    pushError( errorMessage );
+    return QVariant();
+  }
+
+  return query.value( 0 );
 }
 
 QString QgsMssqlProvider::storageType() const

diff --git a/src/providers/mssql/qgsmssqlprovider.h b/src/providers/mssql/qgsmssqlprovider.h
@@ -141,6 +141,7 @@ class QgsMssqlProvider final: public QgsVectorDataProvider
     static QString quotedIdentifier( const QString &value );
 
     QString defaultValueClause( int fieldId ) const override;
+    QVariant defaultValue( int fieldId ) const override;
 
     //! Convert time value
     static QVariant convertTimeValue( const QVariant &value );

diff --git a/tests/src/python/test_provider_mssql.py b/tests/src/python/test_provider_mssql.py
@@ -25,7 +25,8 @@
                        QgsProviderRegistry,
                        NULL,
                        QgsVectorLayerExporter,
-                       QgsCoordinateReferenceSystem)
+                       QgsCoordinateReferenceSystem,
+                       QgsDataProvider)
 
 from qgis.PyQt.QtCore import QDate, QTime, QDateTime, QVariant
 from utilities import unitTestDataPath
@@ -515,6 +516,19 @@ def testInvalidGeometries(self):
         self.assertTrue(vl.isValid())
         self.assertEqual(vl.dataProvider().extent().toString(1), 'Empty')
 
+    def testEvaluateDefaultValueClause(self):
+
+        vl = QgsVectorLayer(
+            '%s table="qgis_test"."someData" sql=' %
+            (self.dbconn), "testdatetimes", "mssql")
+
+        # Activate EvaluateDefaultValues
+        vl.dataProvider().setProviderProperty(QgsDataProvider.EvaluateDefaultValues, True)
+
+        name_index = vl.fields().lookupField('name')
+        defaultValue = vl.dataProvider().defaultValue(name_index)
+        self.assertEqual(defaultValue, 'qgis')
+
     def testPktComposite(self):
         """
         Check that tables with PKs composed of many fields of different types are correctly read and written to