Code:
/ Dotnetfx_Win7_3.5.1 / Dotnetfx_Win7_3.5.1 / 3.5.1 / DEVDIV / depot / DevDiv / releases / Orcas / NetFXw7 / ndp / fx / src / DLinq / Dlinq / SqlClient / Query / SqlBooleanizer.cs / 1 / SqlBooleanizer.cs
using System.Data.Linq.Mapping; namespace System.Data.Linq.SqlClient { ////// Locate cases in which there is a 'Bit' but a 'Predicate' is expected or vice-versa. /// Transform these expressions into expressions of the expected type. /// internal class SqlBooleanizer { private class Booleanizer : SqlBooleanMismatchVisitor { private SqlFactory sql; internal Booleanizer(TypeSystemProvider typeProvider, MetaModel model) { this.sql = new SqlFactory(typeProvider, model); } internal override SqlSelect VisitSelect(SqlSelect select) { // DevDiv 179191 if (select.Where != null && select.Where.NodeType == SqlNodeType.Coalesce) { SqlBinary bin = (SqlBinary)select.Where; if (bin.Right.NodeType == SqlNodeType.Value) { SqlValue value = (SqlValue)bin.Right; if (value.Value != null && value.Value.GetType() == typeof(bool) && (bool)value.Value == false) { select.Where = bin.Left; } } } return base.VisitSelect(select); } internal override SqlExpression ConvertValueToPredicate(SqlExpression valueExpression) { // Transform the 'Bit' expression into a 'Predicate' by forming the // following operation: // OriginalExpr = 1 // Yukon and later could also handle: // OriginalExpr = 'true' // but Sql2000 does not support this. return new SqlBinary(SqlNodeType.EQ, valueExpression.ClrType, sql.TypeProvider.From(typeof(bool)), valueExpression, sql.Value(typeof(bool), valueExpression.SqlType, true, false, valueExpression.SourceExpression) ); } internal override SqlExpression ConvertPredicateToValue(SqlExpression predicateExpression) { // Transform the 'Predicate' expression into a 'Bit' by forming the // following operation: // CASE // WHEN predicateExpression THEN 1 // ELSE NOT(predicateExpression) THEN 0 // ELSE NULL // END // Possible simplification to the generated SQL would be to detect when 'predicateExpression' // is SqlUnary(NOT) and use its operand with the literal 1 and 0 below swapped. SqlExpression valueTrue = sql.ValueFromObject(true, false, predicateExpression.SourceExpression); SqlExpression valueFalse = sql.ValueFromObject(false, false, predicateExpression.SourceExpression); if (SqlExpressionNullability.CanBeNull(predicateExpression) != false) { SqlExpression valueNull = sql.Value(valueTrue.ClrType, valueTrue.SqlType, null, false, predicateExpression.SourceExpression); return new SqlSearchedCase( predicateExpression.ClrType, new SqlWhen[] { new SqlWhen(predicateExpression, valueTrue), new SqlWhen(new SqlUnary(SqlNodeType.Not, predicateExpression.ClrType, predicateExpression.SqlType, predicateExpression, predicateExpression.SourceExpression), valueFalse) }, valueNull, predicateExpression.SourceExpression ); } else { return new SqlSearchedCase( predicateExpression.ClrType, new SqlWhen[] { new SqlWhen(predicateExpression, valueTrue) }, valueFalse, predicateExpression.SourceExpression ); } } } ////// Rationalize boolean expressions for the given node. /// internal static SqlNode Rationalize(SqlNode node, TypeSystemProvider typeProvider, MetaModel model) { return new Booleanizer(typeProvider, model).Visit(node); } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved. using System.Data.Linq.Mapping; namespace System.Data.Linq.SqlClient { ////// Locate cases in which there is a 'Bit' but a 'Predicate' is expected or vice-versa. /// Transform these expressions into expressions of the expected type. /// internal class SqlBooleanizer { private class Booleanizer : SqlBooleanMismatchVisitor { private SqlFactory sql; internal Booleanizer(TypeSystemProvider typeProvider, MetaModel model) { this.sql = new SqlFactory(typeProvider, model); } internal override SqlSelect VisitSelect(SqlSelect select) { // DevDiv 179191 if (select.Where != null && select.Where.NodeType == SqlNodeType.Coalesce) { SqlBinary bin = (SqlBinary)select.Where; if (bin.Right.NodeType == SqlNodeType.Value) { SqlValue value = (SqlValue)bin.Right; if (value.Value != null && value.Value.GetType() == typeof(bool) && (bool)value.Value == false) { select.Where = bin.Left; } } } return base.VisitSelect(select); } internal override SqlExpression ConvertValueToPredicate(SqlExpression valueExpression) { // Transform the 'Bit' expression into a 'Predicate' by forming the // following operation: // OriginalExpr = 1 // Yukon and later could also handle: // OriginalExpr = 'true' // but Sql2000 does not support this. return new SqlBinary(SqlNodeType.EQ, valueExpression.ClrType, sql.TypeProvider.From(typeof(bool)), valueExpression, sql.Value(typeof(bool), valueExpression.SqlType, true, false, valueExpression.SourceExpression) ); } internal override SqlExpression ConvertPredicateToValue(SqlExpression predicateExpression) { // Transform the 'Predicate' expression into a 'Bit' by forming the // following operation: // CASE // WHEN predicateExpression THEN 1 // ELSE NOT(predicateExpression) THEN 0 // ELSE NULL // END // Possible simplification to the generated SQL would be to detect when 'predicateExpression' // is SqlUnary(NOT) and use its operand with the literal 1 and 0 below swapped. SqlExpression valueTrue = sql.ValueFromObject(true, false, predicateExpression.SourceExpression); SqlExpression valueFalse = sql.ValueFromObject(false, false, predicateExpression.SourceExpression); if (SqlExpressionNullability.CanBeNull(predicateExpression) != false) { SqlExpression valueNull = sql.Value(valueTrue.ClrType, valueTrue.SqlType, null, false, predicateExpression.SourceExpression); return new SqlSearchedCase( predicateExpression.ClrType, new SqlWhen[] { new SqlWhen(predicateExpression, valueTrue), new SqlWhen(new SqlUnary(SqlNodeType.Not, predicateExpression.ClrType, predicateExpression.SqlType, predicateExpression, predicateExpression.SourceExpression), valueFalse) }, valueNull, predicateExpression.SourceExpression ); } else { return new SqlSearchedCase( predicateExpression.ClrType, new SqlWhen[] { new SqlWhen(predicateExpression, valueTrue) }, valueFalse, predicateExpression.SourceExpression ); } } } ////// Rationalize boolean expressions for the given node. /// internal static SqlNode Rationalize(SqlNode node, TypeSystemProvider typeProvider, MetaModel model) { return new Booleanizer(typeProvider, model).Visit(node); } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved.
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- ConnectionStringsSection.cs
- PropertyMetadata.cs
- ToolStripDesignerAvailabilityAttribute.cs
- HostingEnvironmentSection.cs
- PrivilegeNotHeldException.cs
- FuncCompletionCallbackWrapper.cs
- SmtpLoginAuthenticationModule.cs
- FileUtil.cs
- EnumConverter.cs
- NamedElement.cs
- SqlClientWrapperSmiStream.cs
- shaperfactoryquerycacheentry.cs
- TargetInvocationException.cs
- ViewBox.cs
- SplitContainer.cs
- ProcessHost.cs
- HttpHandler.cs
- TypeDescriptionProviderAttribute.cs
- URLMembershipCondition.cs
- CodeGotoStatement.cs
- SecurityContextSecurityTokenAuthenticator.cs
- BinaryObjectInfo.cs
- CfgParser.cs
- PngBitmapEncoder.cs
- XmlSchemaValidator.cs
- WebUtil.cs
- FunctionImportElement.cs
- SrgsRuleRef.cs
- XmlSchemaComplexContentExtension.cs
- DiagnosticSection.cs
- ObjectNavigationPropertyMapping.cs
- StringExpressionSet.cs
- EmissiveMaterial.cs
- CompletedAsyncResult.cs
- WaitHandle.cs
- SelectionManager.cs
- PlainXmlSerializer.cs
- GridViewHeaderRowPresenter.cs
- MinMaxParagraphWidth.cs
- EdmScalarPropertyAttribute.cs
- MenuItemBindingCollection.cs
- TimeSpanValidatorAttribute.cs
- WindowsIdentity.cs
- ColumnMap.cs
- MultipartContentParser.cs
- TextInfo.cs
- PersonalizationAdministration.cs
- StylusCollection.cs
- UnsafePeerToPeerMethods.cs
- MeshGeometry3D.cs
- CellConstant.cs
- GridSplitter.cs
- XmlChildEnumerator.cs
- BrowserCapabilitiesFactory.cs
- DataFieldEditor.cs
- DelegateTypeInfo.cs
- SocketPermission.cs
- TreeSet.cs
- SafeNativeMethods.cs
- DependsOnAttribute.cs
- ReferenceConverter.cs
- DispatcherHookEventArgs.cs
- ComboBox.cs
- WindowsTab.cs
- CompoundFileIOPermission.cs
- MessageEncoder.cs
- MsmqMessage.cs
- VectorConverter.cs
- FontFamily.cs
- UseManagedPresentationBindingElement.cs
- CompiledXpathExpr.cs
- DescendentsWalker.cs
- XamlStream.cs
- Ipv6Element.cs
- DefaultWorkflowLoaderService.cs
- AddingNewEventArgs.cs
- ButtonField.cs
- DataControlFieldHeaderCell.cs
- GridViewHeaderRowPresenter.cs
- TemplateComponentConnector.cs
- DeviceContext.cs
- MetadataItemEmitter.cs
- PageThemeBuildProvider.cs
- ButtonField.cs
- RepeaterDataBoundAdapter.cs
- Crc32Helper.cs
- StorageFunctionMapping.cs
- OrderedDictionaryStateHelper.cs
- ToolStripControlHost.cs
- Permission.cs
- XamlStream.cs
- ObjectStateFormatter.cs
- PointAnimation.cs
- PeerDuplexChannelListener.cs
- CodeCommentStatement.cs
- TextBoxBase.cs
- serverconfig.cs
- SHA256.cs
- ThemeableAttribute.cs
- IncrementalReadDecoders.cs