[mssql] Optimise field retrieval in browser, don't require opening la…

…yers
qgis · Feb 23, 2025 · 555bbe3 · 555bbe3
1 parent f3c37f5
commit 555bbe3
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Showing 2 changed files with 30 additions and 1 deletion.
diff --git a/src/providers/mssql/qgsmssqlproviderconnection.cpp b/src/providers/mssql/qgsmssqlproviderconnection.cpp
@@ -508,14 +508,42 @@ SELECT %4 UPPER( %1.STGeometryType()), %1.STSrid,
   return tables;
 }
 
+QgsFields QgsMssqlProviderConnection::fields( const QString &schema, const QString &table, QgsFeedback *feedback ) const
+{
+  if ( feedback && feedback->isCanceled() )
+  {
+    return QgsFields();
+  }
+
+  const QgsDataSourceUri dsUri { uri() };
+
+  // connect to database
+  std::shared_ptr<QgsMssqlDatabase> db = QgsMssqlDatabase::connectDb( dsUri );
+  if ( !db->isValid() )
+  {
+    throw QgsProviderConnectionException( QObject::tr( "Connection to %1 failed: %2" )
+                                            .arg( uri(), db->errorText() ) );
+  }
+
+  QgsMssqlDatabase::FieldDetails details;
+
+  QString error;
+  const bool result = db->loadFields( details, schema, table, error );
+  if ( !result )
+  {
+    throw QgsProviderConnectionException( QObject::tr( "Error retrieving fields information: %1" ).arg( error ) );
+  }
+
+  return details.attributeFields;
+}
+
 QStringList QgsMssqlProviderConnection::schemas() const
 {
   checkCapability( Capability::Schemas );
   QStringList schemas;
 
   const QgsDataSourceUri connUri( uri() );
 
-  const QgsDataSourceUri dsUri { uri() };
   const QString sql {
     QStringLiteral(
       R"raw(

diff --git a/src/providers/mssql/qgsmssqlproviderconnection.h b/src/providers/mssql/qgsmssqlproviderconnection.h
@@ -61,6 +61,7 @@ class QgsMssqlProviderConnection : public QgsAbstractDatabaseProviderConnection
     QgsAbstractDatabaseProviderConnection::QueryResult execSql( const QString &sql, QgsFeedback *feedback ) const override;
     QList<QgsAbstractDatabaseProviderConnection::TableProperty> tables( const QString &schema, const TableFlags &flags = TableFlags(), QgsFeedback *feedback = nullptr ) const override;
     QgsAbstractDatabaseProviderConnection::TableProperty table( const QString &schema, const QString &table, QgsFeedback *feedback = nullptr ) const override;
+    QgsFields fields( const QString &schema, const QString &table, QgsFeedback *feedback = nullptr ) const override;
     QStringList schemas() const override;
     void store( const QString &name ) const override;
     void remove( const QString &name ) const override;