connectivity/source/drivers/hsqldb/HView.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
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   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20
  21 #include <hsqldb/HView.hxx>
  22 #include <hsqldb/HTools.hxx>
  23
  24 #include <propertyids.hxx>
  25
  26 #include <connectivity/dbexception.hxx>
  27 #include <connectivity/dbtools.hxx>
  28
  29 #include <com/sun/star/lang/WrappedTargetException.hpp>
  30 #include <com/sun/star/lang/DisposedException.hpp>
  31 #include <com/sun/star/sdbc/XRow.hpp>
  32 #include <com/sun/star/sdbc/SQLException.hpp>
  33
  34 #include <cppuhelper/exc_hlp.hxx>
  35 #include <tools/diagnose_ex.h>
  36 #include <unotools/sharedunocomponent.hxx>
  37
  38
  39 namespace connectivity { namespace hsqldb
  40 {
  41
  42
  43     using ::com::sun::star::uno::Reference;
  44     using ::com::sun::star::uno::UNO_QUERY_THROW;
  45     using ::com::sun::star::uno::Exception;
  46     using ::com::sun::star::uno::RuntimeException;
  47     using ::com::sun::star::uno::Any;
  48     using ::com::sun::star::sdbc::SQLException;
  49     using ::com::sun::star::sdbc::XConnection;
  50     using ::com::sun::star::lang::WrappedTargetException;
  51     using ::com::sun::star::sdbc::XResultSet;
  52     using ::com::sun::star::sdbc::XStatement;
  53     using ::com::sun::star::lang::DisposedException;
  54     using ::com::sun::star::sdbc::XRow;
  55
  56     HView::HView( const Reference< XConnection >& _rxConnection, bool _bCaseSensitive,
  57         const OUString& _rSchemaName, const OUString& _rName )
  58         :HView_Base( _bCaseSensitive, _rName, _rxConnection->getMetaData(), OUString(), _rSchemaName, OUString() )
  59         ,m_xConnection( _rxConnection )
  60     {
  61     }
  62
  63
  64     HView::~HView()
  65     {
  66     }
  67
  68
  69     IMPLEMENT_FORWARD_XINTERFACE2( HView, HView_Base, HView_IBASE )
  70     IMPLEMENT_FORWARD_XTYPEPROVIDER2( HView, HView_Base, HView_IBASE )
  71
  72
  73     void SAL_CALL HView::alterCommand( const OUString& _rNewCommand )
  74     {
  75         // not really atomic ... as long as we do not have something like
  76         //   ALTER VIEW <name> TO <command>
  77         // in HSQL, we need to do it this way ...
  78         //
  79         // I can imagine scenarios where this fails, e.g. when dropping the view
  80         // succeeds, re-creating it fails, some other thread alters a table which
  81         // the view was based on, and then we try to restore the view with the
  82         // original command, which then fails, too.
  83         //
  84         // However, there's not much chance to prevent this kind of errors without
  85         // backend support.
  86
  87         OUString sQualifiedName( ::dbtools::composeTableName(
  88             m_xMetaData, m_CatalogName, m_SchemaName, m_Name, true, ::dbtools::EComposeRule::InDataManipulation ) );
  89
  90         ::utl::SharedUNOComponent< XStatement > xStatement; xStatement.set( m_xConnection->createStatement(), UNO_QUERY_THROW );
  91
  92         // create a statement which can be used to re-create the original view, in case
  93         // dropping it succeeds, but creating it with a new statement fails
  94         OUStringBuffer aRestoreCommand;
  95         aRestoreCommand.append( "CREATE VIEW " );
  96         aRestoreCommand.append     ( sQualifiedName );
  97         aRestoreCommand.append( " AS " );
  98         aRestoreCommand.append     ( impl_getCommand_throwSQLException() );
  99         OUString sRestoreCommand( aRestoreCommand.makeStringAndClear() );
 100
 101         bool bDropSucceeded( false );
 102         try
 103         {
 104             // drop the existing view
 105             OUStringBuffer aCommand;
 106             aCommand.append( "DROP VIEW " );
 107             aCommand.append     ( sQualifiedName );
 108             xStatement->execute( aCommand.makeStringAndClear() );
 109             bDropSucceeded = true;
 110
 111             // create a new one with the same name
 112             aCommand.append( "CREATE VIEW " );
 113             aCommand.append     ( sQualifiedName );
 114             aCommand.append( " AS " );
 115             aCommand.append     ( _rNewCommand );
 116             xStatement->execute( aCommand.makeStringAndClear() );
 117         }
 118         catch( const SQLException& )
 119         {
 120             if ( bDropSucceeded )
 121                 // drop succeeded, but creation failed -> re-create the view with the original
 122                 // statement
 123                 xStatement->execute( sRestoreCommand );
 124             throw;
 125         }
 126         catch( const RuntimeException& )
 127         {
 128             if ( bDropSucceeded )
 129                 xStatement->execute( sRestoreCommand );
 130             throw;
 131         }
 132         catch( const Exception& )
 133         {
 134             DBG_UNHANDLED_EXCEPTION("connectivity.hsqldb");
 135             if ( bDropSucceeded )
 136                 xStatement->execute( sRestoreCommand );
 137         }
 138     }
 139
 140
 141     void SAL_CALL HView::getFastPropertyValue( Any& _rValue, sal_Int32 _nHandle ) const
 142     {
 143         if ( _nHandle == PROPERTY_ID_COMMAND )
 144         {
 145             // retrieve the very current command, don't rely on the base classes cached value
 146             // (which we initialized empty, anyway)
 147             _rValue <<= impl_getCommand_wrapSQLException();
 148             return;
 149         }
 150
 151         HView_Base::getFastPropertyValue( _rValue, _nHandle );
 152     }
 153
 154     OUString HView::impl_getCommand() const
 155     {
 156         OUStringBuffer aCommand;
 157         aCommand.append( "SELECT VIEW_DEFINITION FROM INFORMATION_SCHEMA.SYSTEM_VIEWS " );
 158         HTools::appendTableFilterCrit( aCommand, m_CatalogName, m_SchemaName, m_Name, false );
 159         ::utl::SharedUNOComponent< XStatement > xStatement; xStatement.set( m_xConnection->createStatement(), UNO_QUERY_THROW );
 160         Reference< XResultSet > xResult( xStatement->executeQuery( aCommand.makeStringAndClear() ), css::uno::UNO_SET_THROW );
 161         if ( !xResult->next() )
 162         {
 163             // hmm. There is no view the name as we know it. Can only mean some other instance
 164             // dropped this view meanwhile...
 165             throw DisposedException();
 166         }
 167
 168         Reference< XRow > xRow( xResult, UNO_QUERY_THROW );
 169         return xRow->getString( 1 );
 170     }
 171
 172     OUString HView::impl_getCommand_wrapSQLException() const
 173     {
 174         OUString sCommand;
 175
 176         try
 177         {
 178             sCommand = impl_getCommand();
 179         }
 180         catch( const RuntimeException& )
 181         {
 182             throw;
 183         }
 184         catch( const SQLException& e )
 185         {
 186             throw WrappedTargetException( e.Message, static_cast< XAlterView* >( const_cast< HView* >( this ) ), ::cppu::getCaughtException() );
 187         }
 188         catch( const Exception& )
 189         {
 190             DBG_UNHANDLED_EXCEPTION("connectivity.hsqldb");
 191         }
 192
 193         return sCommand;
 194     }
 195
 196     OUString HView::impl_getCommand_throwSQLException() const
 197     {
 198         OUString sCommand;
 199
 200         try
 201         {
 202             sCommand = impl_getCommand();
 203         }
 204         catch( const RuntimeException& )
 205         {
 206             throw;
 207         }
 208         catch( const SQLException& )
 209         {
 210             throw;
 211         }
 212         catch( const Exception& )
 213         {
 214             DBG_UNHANDLED_EXCEPTION("connectivity.hsqldb");
 215         }
 216
 217         return sCommand;
 218     }
 219
 220 } } // namespace connectivity::hsqldb
 221
 222
 223 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */