Rework handling of 'not null' filter expression in HANA

qgis · Dec 7, 2020 · 00b7554 · 00b7554
1 parent a9fb9df
commit 00b7554
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Showing 3 changed files with 56 additions and 18 deletions.
diff --git a/src/providers/hana/qgshanaexpressioncompiler.cpp b/src/providers/hana/qgshanaexpressioncompiler.cpp
@@ -132,6 +132,28 @@ QgsSqlExpressionCompiler::Result QgsHanaExpressionCompiler::compileNode(
       }
     }
     break;
+    case QgsExpressionNode::ntUnaryOperator:
+      {
+        const QgsExpressionNodeUnaryOperator *unaryOp = static_cast<const QgsExpressionNodeUnaryOperator *>( node );
+        switch ( unaryOp->op() )
+        {
+            case QgsExpressionNodeUnaryOperator::uoNot:
+            {
+                Result resRight = compileNode( unaryOp->operand(), result );
+                if ( "NULL" == result.toUpper() )
+                {
+                  result.clear();
+                  return Fail;
+                }
+                result = "NOT " + result;
+
+                return resRight;
+            }
+            case QgsExpressionNodeUnaryOperator::uoMinus:
+              break;
+        }
+      }
+      break;
     case QgsExpressionNode::ntBinaryOperator:
     {
       const QgsExpressionNodeBinaryOperator *binOp( static_cast<const QgsExpressionNodeBinaryOperator *>( node ) );
@@ -144,6 +166,14 @@ QgsSqlExpressionCompiler::Result QgsHanaExpressionCompiler::compileNode(
       if ( resLeft == Fail || resRight == Fail )
         return Fail;
 
+      // NULL can not appear on the left, only as part of IS NULL or IS NOT NULL
+      if ( "NULL" == opLeft.toUpper() )
+        return Fail;
+      // NULL can only be on the right for IS and IS NOT
+      if ( "NULL" == opRight.toUpper() &&
+           ( binOp->op() != QgsExpressionNodeBinaryOperator::boIs && binOp->op() != QgsExpressionNodeBinaryOperator::boIsNot ) )
+        return Fail;
+
       switch ( binOp->op() )
       {
         case QgsExpressionNodeBinaryOperator::boMod:

diff --git a/src/providers/hana/qgshanafeatureiterator.cpp b/src/providers/hana/qgshanafeatureiterator.cpp
@@ -339,9 +339,10 @@ QString QgsHanaFeatureIterator::buildSqlQuery( const QgsFeatureRequest &request
   QString sqlFilter;
   // Set spatial filter
   if ( !( filterRect.isNull() || filterRect.isEmpty() ) && mSource->isSpatial() && mHasGeometryColumn )
-  {
     sqlFilter = getBBOXFilter( filterRect, QgsHanaUtils::toHANAVersion( mConnRef->getDatabaseVersion() ) );
-  }
+
+  if ( !mSource->mQueryWhereClause.isEmpty() )
+    sqlFilter = andWhereClauses( sqlFilter, mSource->mQueryWhereClause );
 
   // Set fid filter
   if ( !mFidColumn.isEmpty() )
@@ -375,22 +376,31 @@ QString QgsHanaFeatureIterator::buildSqlQuery( const QgsFeatureRequest &request
     if ( QgsSettings().value( QStringLiteral( "qgis/compileExpressions" ), true ).toBool() )
     {
       QgsHanaExpressionCompiler compiler = QgsHanaExpressionCompiler( mSource );
-
       QgsSqlExpressionCompiler::Result result = compiler.compile( request.filterExpression() );
-
-      if ( result == QgsSqlExpressionCompiler::Complete || result == QgsSqlExpressionCompiler::Partial )
+      switch(result)
+      {
+      case QgsSqlExpressionCompiler::Result::Complete:
+      case QgsSqlExpressionCompiler::Result::Partial:
       {
-        QString filterExpr = compiler.result();
-        if ( !filterExpr.isEmpty() )
-        {
-          sqlFilter = andWhereClauses( sqlFilter, filterExpr );
-          //if only partial success when compiling expression, we need to double-check results
-          //using QGIS' expressions
-          mExpressionCompiled = ( result == QgsSqlExpressionCompiler::Complete );
-          mCompileStatus = ( mExpressionCompiled ? Compiled : PartiallyCompiled );
-        }
+          QString filterExpr = compiler.result();
+          if ( !filterExpr.isEmpty() )
+          {
+            sqlFilter = andWhereClauses( sqlFilter, filterExpr );
+            //if only partial success when compiling expression, we need to double-check results
+            //using QGIS' expressions
+            mExpressionCompiled = ( result == QgsSqlExpressionCompiler::Result::Complete );
+            mCompileStatus = ( mExpressionCompiled ? Compiled : PartiallyCompiled );
+          }
+      }
+      break;
+      case QgsSqlExpressionCompiler::Result::Fail:
+          QgsDebugMsg(QStringLiteral("Unable to compile filter expression: '%1'")
+                      .arg(request.filterExpression()->expression()).toStdString().c_str());
+          break;
+      case QgsSqlExpressionCompiler::Result::None:
+          break;
       }
-      if ( result != QgsSqlExpressionCompiler::Complete )
+      if ( result != QgsSqlExpressionCompiler::Result::Complete )
       {
         //can't apply limit at provider side as we need to check all results using QGIS expressions
         limitAtProvider = false;
@@ -402,9 +412,6 @@ QString QgsHanaFeatureIterator::buildSqlQuery( const QgsFeatureRequest &request
     }
   }
 
-  if ( !mSource->mQueryWhereClause.isEmpty() )
-    sqlFilter = andWhereClauses( sqlFilter, mSource->mQueryWhereClause );
-
   if ( !sqlFilter.isEmpty() )
     sql += QStringLiteral( " WHERE " ) + sqlFilter;
 

diff --git a/tests/src/python/test_provider_hana.py b/tests/src/python/test_provider_hana.py
@@ -128,6 +128,7 @@ def uncompiledFilters(self):
             'NULL or false',
             'NULL or true',
             'NULL or NULL',
+            'not null',
             '\'x\' || "name" IS NOT NULL',
             '\'x\' || "name" IS NULL',
             'radians(cnt) < 2',