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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   9  * This file incorporates work covered by the following license notice:
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  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
  33 #include <cppuhelper/exc_hlp.hxx>
  34 #include <tools/diagnose_ex.h>
  35 #include <unotools/sharedunocomponent.hxx>
  36
  37 //........................................................................
  38 namespace connectivity { namespace hsqldb
  39 {
  40 //........................................................................
  41
  42     using ::com::sun::star::uno::Reference;
  43     using ::com::sun::star::uno::UNO_QUERY;
  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::uno::makeAny;
  49     using ::com::sun::star::sdbc::XDatabaseMetaData;
  50     using ::com::sun::star::sdbc::SQLException;
  51     using ::com::sun::star::sdbc::XConnection;
  52     using ::com::sun::star::lang::WrappedTargetException;
  53     using ::com::sun::star::sdbc::XResultSet;
  54     using ::com::sun::star::sdbc::XStatement;
  55     using ::com::sun::star::lang::DisposedException;
  56     using ::com::sun::star::sdbc::XRow;
  57
  58     //====================================================================
  59     //= HView
  60     //====================================================================
  61     //--------------------------------------------------------------------
  62     HView::HView( const Reference< XConnection >& _rxConnection, sal_Bool _bCaseSensitive,
  63         const OUString& _rSchemaName, const OUString& _rName )
  64         :HView_Base( _bCaseSensitive, _rName, _rxConnection->getMetaData(), 0, OUString(), _rSchemaName, OUString() )
  65         ,m_xConnection( _rxConnection )
  66     {
  67     }
  68
  69     //--------------------------------------------------------------------
  70     HView::~HView()
  71     {
  72     }
  73
  74     //--------------------------------------------------------------------
  75     IMPLEMENT_FORWARD_XINTERFACE2( HView, HView_Base, HView_IBASE )
  76     IMPLEMENT_FORWARD_XTYPEPROVIDER2( HView, HView_Base, HView_IBASE )
  77
  78     //--------------------------------------------------------------------
  79     void SAL_CALL HView::alterCommand( const OUString& _rNewCommand ) throw (SQLException, RuntimeException)
  80     {
  81         // not really atomic ... as long as we do not have something like
  82         //   ALTER VIEW <name> TO <command>
  83         // in HSQL, we need to do it this way ...
  84         //
  85         // I can imagine scenarios where this fails, e.g. when dropping the view
  86         // succeedes, re-creating it fails, some other thread alters a table which
  87         // the view was based on, and then we try to restore the view with the
  88         // original command, which then fails, too.
  89         //
  90         // However, there's not much chance to prevent this kind of errors without
  91         // backend support.
  92
  93         OUString sQualifiedName( ::dbtools::composeTableName(
  94             m_xMetaData, m_CatalogName, m_SchemaName, m_Name, true, ::dbtools::eInDataManipulation ) );
  95
  96         ::utl::SharedUNOComponent< XStatement > xStatement; xStatement.set( m_xConnection->createStatement(), UNO_QUERY_THROW );
  97
  98         // create a statement which can be used to re-create the original view, in case
  99         // dropping it succeeds, but creating it with a new statement fails
 100         OUStringBuffer aRestoreCommand;
 101         aRestoreCommand.appendAscii( "CREATE VIEW " );
 102         aRestoreCommand.append     ( sQualifiedName );
 103         aRestoreCommand.appendAscii( " AS " );
 104         aRestoreCommand.append     ( impl_getCommand_throw( true ) );
 105         OUString sRestoreCommand( aRestoreCommand.makeStringAndClear() );
 106
 107         bool bDropSucceeded( false );
 108         try
 109         {
 110             // drop the existing view
 111             OUStringBuffer aCommand;
 112             aCommand.appendAscii( "DROP VIEW " );
 113             aCommand.append     ( sQualifiedName );
 114             xStatement->execute( aCommand.makeStringAndClear() );
 115             bDropSucceeded = true;
 116
 117             // create a new one with the same name
 118             aCommand.appendAscii( "CREATE VIEW " );
 119             aCommand.append     ( sQualifiedName );
 120             aCommand.appendAscii( " AS " );
 121             aCommand.append     ( _rNewCommand );
 122             xStatement->execute( aCommand.makeStringAndClear() );
 123         }
 124         catch( const SQLException& )
 125         {
 126             if ( bDropSucceeded )
 127                 // drop succeeded, but creation failed -> re-create the view with the original
 128                 // statemnet
 129                 xStatement->execute( sRestoreCommand );
 130             throw;
 131         }
 132         catch( const RuntimeException& )
 133         {
 134             if ( bDropSucceeded )
 135                 xStatement->execute( sRestoreCommand );
 136             throw;
 137         }
 138         catch( const Exception& )
 139         {
 140             if ( bDropSucceeded )
 141                 xStatement->execute( sRestoreCommand );
 142             DBG_UNHANDLED_EXCEPTION();
 143         }
 144     }
 145
 146     //--------------------------------------------------------------------
 147     void SAL_CALL HView::getFastPropertyValue( Any& _rValue, sal_Int32 _nHandle ) const
 148     {
 149         if ( _nHandle == PROPERTY_ID_COMMAND )
 150         {
 151             // retrieve the very current command, don't rely on the base classes cached value
 152             // (which we initialized empty, anyway)
 153             _rValue <<= impl_getCommand_throw( false );
 154             return;
 155         }
 156
 157         HView_Base::getFastPropertyValue( _rValue, _nHandle );
 158     }
 159
 160     //--------------------------------------------------------------------
 161     OUString HView::impl_getCommand_throw( bool _bAllowSQLException ) const
 162     {
 163         OUString sCommand;
 164
 165         try
 166         {
 167             OUStringBuffer aCommand;
 168             aCommand.appendAscii( "SELECT VIEW_DEFINITION FROM INFORMATION_SCHEMA.SYSTEM_VIEWS " );
 169             HTools::appendTableFilterCrit( aCommand, m_CatalogName, m_SchemaName, m_Name, false );
 170             ::utl::SharedUNOComponent< XStatement > xStatement; xStatement.set( m_xConnection->createStatement(), UNO_QUERY_THROW );
 171             Reference< XResultSet > xResult( xStatement->executeQuery( aCommand.makeStringAndClear() ), UNO_QUERY_THROW );
 172             if ( !xResult->next() )
 173             {
 174                 // hmm. There is no view view the name as we know it. Can only mean some other instance
 175                 // dropped this view meanwhile ...
 176                 throw DisposedException();
 177             }
 178
 179             Reference< XRow > xRow( xResult, UNO_QUERY_THROW );
 180             sCommand = xRow->getString( 1 );
 181         }
 182         catch( const RuntimeException& ) { throw; }
 183         catch( const SQLException& e )
 184         {
 185             if ( _bAllowSQLException )
 186                 throw;
 187             throw WrappedTargetException( e.Message, static_cast< XAlterView* >( const_cast< HView* >( this ) ), ::cppu::getCaughtException() );
 188         }
 189         catch( const Exception& )
 190         {
 191             DBG_UNHANDLED_EXCEPTION();
 192         }
 193
 194         return sCommand;
 195     }
 196
 197 //........................................................................
 198 } } // namespace connectivity::hsqldb
 199 //........................................................................
 200
 201 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */