[mssql] Followup a76359, fix provider methods like featureCount,

uniqueValues, etc not working when using DSN for connection

Author: nyalldawson

src/providers/mssql/qgsmssqlprovider.cpp

@@ -350,6 +350,11 @@ void QgsMssqlProvider::loadMetadata()
   mSRId = 0;
   mWkbType = QGis::WKBUnknown;
 
+  if ( !mDatabase.isOpen() )
+  {
+    mDatabase = GetDatabase( mService, mHost, mDatabaseName, mUserName, mPassword );
+  }
+
   QSqlQuery query = QSqlQuery( mDatabase );
   query.setForwardOnly( true );
   if ( !query.exec( QString( "select f_geometry_column, coord_dimension, srid, geometry_type from geometry_columns where f_table_schema = '%1' and f_table_name = '%2'" ).arg( mSchemaName, mTableName ) ) )
@@ -368,7 +373,12 @@ void QgsMssqlProvider::loadFields()
 {
   mAttributeFields.clear();
   mDefaultValues.clear();
+
   // get field spec
+  if ( !mDatabase.isOpen() )
+  {
+    mDatabase = GetDatabase( mService, mHost, mDatabaseName, mUserName, mPassword );
+  }
   QSqlQuery query = QSqlQuery( mDatabase );
   query.setForwardOnly( true );
   if ( !query.exec( QString( "exec sp_columns @table_name = N'%1', @table_owner = '%2'" ).arg( mTableName, mSchemaName ) ) )
@@ -532,6 +542,10 @@ QVariant QgsMssqlProvider::minimumValue( int index )
     sql += QString( " where (%1)" ).arg( mSqlWhereClause );
   }
 
+  if ( !mDatabase.isOpen() )
+  {
+    mDatabase = GetDatabase( mService, mHost, mDatabaseName, mUserName, mPassword );
+  }
   QSqlQuery query = QSqlQuery( mDatabase );
   query.setForwardOnly( true );
 
@@ -563,6 +577,10 @@ QVariant QgsMssqlProvider::maximumValue( int index )
     sql += QString( " where (%1)" ).arg( mSqlWhereClause );
   }
 
+  if ( !mDatabase.isOpen() )
+  {
+    mDatabase = GetDatabase( mService, mHost, mDatabaseName, mUserName, mPassword );
+  }
   QSqlQuery query = QSqlQuery( mDatabase );
   query.setForwardOnly( true );
 
@@ -603,6 +621,10 @@ void QgsMssqlProvider::uniqueValues( int index, QList<QVariant> &uniqueValues, i
     sql += QString( " where (%1)" ).arg( mSqlWhereClause );
   }
 
+  if ( !mDatabase.isOpen() )
+  {
+    mDatabase = GetDatabase( mService, mHost, mDatabaseName, mUserName, mPassword );
+  }
   QSqlQuery query = QSqlQuery( mDatabase );
   query.setForwardOnly( true );
 
@@ -631,6 +653,10 @@ void QgsMssqlProvider::UpdateStatistics( bool estimate )
   // get features to calculate the statistics
   QString statement;
 
+  if ( !mDatabase.isOpen() )
+  {
+    mDatabase = GetDatabase( mService, mHost, mDatabaseName, mUserName, mPassword );
+  }
   QSqlQuery query = QSqlQuery( mDatabase );
   query.setForwardOnly( true );
 
@@ -758,6 +784,10 @@ long QgsMssqlProvider::featureCount() const
 
   // If there is no subset set we can get the count from the system tables.
   // Which is faster then doing select count(*)
+  if ( !mDatabase.isOpen() )
+  {
+    mDatabase = GetDatabase( mService, mHost, mDatabaseName, mUserName, mPassword );
+  }
   QSqlQuery query = QSqlQuery( mDatabase );
   query.setForwardOnly( true );
 
@@ -1419,6 +1449,10 @@ QgsCoordinateReferenceSystem QgsMssqlProvider::crs()
       return mCrs;
 
     // try to load crs from the database tables as a fallback
+    if ( !mDatabase.isOpen() )
+    {
+      mDatabase = GetDatabase( mService, mHost, mDatabaseName, mUserName, mPassword );
+    }
     QSqlQuery query = QSqlQuery( mDatabase );
     query.setForwardOnly( true );
     bool execOk = query.exec( QString( "select srtext from spatial_ref_sys where srid = %1" ).arg( QString::number( mSRId ) ) );
@@ -1472,6 +1506,10 @@ bool QgsMssqlProvider::setSubsetString( const QString& theSQL, bool )
     sql += QString( " where %1" ).arg( mSqlWhereClause );
   }
 
+  if ( !mDatabase.isOpen() )
+  {
+    mDatabase = GetDatabase( mService, mHost, mDatabaseName, mUserName, mPassword );
+  }
   QSqlQuery query = QSqlQuery( mDatabase );
   query.setForwardOnly( true );
   if ( !query.exec( sql ) )

src/providers/mssql/qgsmssqlprovider.h

@@ -290,7 +290,7 @@ class QgsMssqlProvider : public QgsVectorDataProvider
     QGis::WkbType mWkbType;
 
     // The database object
-    QSqlDatabase mDatabase;
+    mutable QSqlDatabase mDatabase;
 
     // The current sql query
     QSqlQuery mQuery;