TDbiResultSet Class Reference

Concept Abstract base class representing the Result of a single database query. If query suceeded the Result will hold (own) a vector of table row objects that correspond to result of the query. It will also own a TDbiValidityRec that gives the range over which the result is valid. More...

#include <TDbiResultSet.hxx>

Inheritance diagram for TDbiResultSet:

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Collaboration diagram for TDbiResultSet:

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List of all members.

Public Member Functions
	TDbiResultSet (TDbiInRowStream resultSet=0, const TDbiValidityRec vrec=0, const string &sqlQualifiers="")
virtual	~TDbiResultSet ()
virtual Bool_t	CanReuse () const
virtual Bool_t	CanSave () const
virtual void	Connect () const
virtual TDbiResultKey *	CreateKey () const =0
virtual void	Disconnect () const
const TDbiExceptionLog &	GetExceptionLog () const
Int_t	GetID () const
virtual const TDbiResultKey *	GetKey () const
virtual UInt_t	GetNumAggregates () const =0
virtual UInt_t	GetNumClients () const
virtual UInt_t	GetNumRows () const =0
const string &	GetSqlQualifiers () const
virtual const TDbiTableRow *	GetTableRow (UInt_t rowNum) const =0
virtual const TDbiTableRow *	GetTableRowByIndex (UInt_t index) const
virtual const TDbiValidityRec &	GetValidityRec (const TDbiTableRow *=0) const
virtual const TDbiValidityRec &	GetValidityRecGlobal () const
Bool_t	IsExtendedContext () const
virtual Bool_t	Owns (const TDbiTableRow *) const
Bool_t	ResultsFromDb () const
virtual const string &	TableName () const
void	CaptureExceptionLog (UInt_t startFrom)
virtual Bool_t	CanDelete (const TDbiResultSet *res=0)
	Return true if no clients and unlikely to be reused.
virtual Bool_t	Satisfies (const TVldContext &vc, const TDbi::Task &task)
virtual Bool_t	Satisfies (const string &)
virtual Bool_t	Satisfies (const TDbiValidityRec &, const string &="")
virtual void	GenerateKey ()
	Key handling.
virtual void	Streamer (TDbiBinaryFile &file)
virtual void	SetCanReuse (Bool_t reuse)
Protected Member Functions
void	SetResultsFromDb ()
void	BuildLookUpTable () const
Bool_t	LookUpBuilt () const
virtual void	SetTableName (const string &tableName)
virtual void	SetValidityRec (const TDbiValidityRec &vRec)
Private Attributes
Int_t	fID
	Unique ID within the current job.
Bool_t	fCanReuse
TDbiValidityRec	fEffVRec
IndexToRow_t	fIndexKeys
const TDbiResultKey *	fKey
Bool_t	fResultsFromDb
	True is at least part didn't come from cache.
Int_t	fNumClients
string	fTableName
string	fSqlQualifiers
TDbiExceptionLog	fExceptionLog
	Exception log produced when query was executed.
Static Private Attributes
static Int_t	fgLastID
	Used to allocate unique ID within the current job.

Detailed Description

Concept Abstract base class representing the Result of a single database query. If query suceeded the Result will hold (own) a vector of table row objects that correspond to result of the query. It will also own a TDbiValidityRec that gives the range over which the result is valid.

Purpose To provide suitable objects to cache. TDbiResultSets can be checked to see if they satisfy new queries. Contact: A.Finch@lancaster.ac.uk

Definition at line 49 of file TDbiResultSet.hxx.

Constructor & Destructor Documentation

TDbiResultSet::TDbiResultSet	(	TDbiInRowStream *	resultSet = `0`,
		const TDbiValidityRec *	vrec = `0`,
		const string &	sqlQualifiers = `""`
	)

Definition at line 50 of file TDbiResultSet.cxx.

References fEffVRec, fTableName, SK_DBI_Trace, and TDbiRowStream::TableNameTc().

00052                                                   :
00053 fID(++fgLastID),
00054 fCanReuse(kTRUE),
00055 fEffVRec(0),
00056 fKey(0),
00057 fResultsFromDb(kFALSE),
00058 fNumClients(0),
00059 fTableName("Unknown"),
00060 fSqlQualifiers(sqlQualifiers)
00061 {
00062 //
00063 //
00064 //  Purpose:  Default constructor
00065 //
00066 //  Arguments:
00067 //      resultSet     in   Pointer TDbiInRowStream from query. May be null.
00068 //      vrec          in   Pointer to validity record from query.
00069 //                         May be null
00070 //      sqlQualifier  in   Extended Context sql qualifiers
00071 //
00072 //  Return:    n/a
00073 //
00074 //  Contact:   N. West
00075 //
00076 //  Specification:-
00077 //  =============
00078 //
00079 //  o Create Result from TDbiInRowStream generated by query.
00080 
00081 
00082 //  Program Notes:-
00083 //  =============
00084 
00085 // None.
00086 
00087 
00088   SK_DBI_Trace( "Creating TDbiResultSet" << "  ");
00089 
00090   if ( vrec ) fEffVRec = *vrec;
00091   if ( resultSet ) fTableName = resultSet->TableNameTc();
00092 
00093 }

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TDbiResultSet::~TDbiResultSet ( ) [virtual]

Definition at line 97 of file TDbiResultSet.cxx.

References fIndexKeys, fKey, fNumClients, SK_DBI_Trace, and SK_DBI_Warn.

00097                               {
00098 //
00099 //
00100 //  Purpose: Destructor
00101 //
00102 //  Arguments:
00103 //    None.
00104 //
00105 //  Return:    n/a
00106 //
00107 //  Contact:   N. West
00108 //
00109 //  Specification:-
00110 //  =============
00111 //
00112 //  o  Destroy Result.
00113 
00114 
00115 //  Program Notes:-
00116 //  =============
00117 
00118 //  None.
00119 
00120 
00121   SK_DBI_Trace( "Destroying TDbiResultSet." << "  ");
00122 
00123   if ( fNumClients ) SK_DBI_Warn(  "Warning: Destroying TDbiResultSet with " << fNumClients
00124     << " clients " << "  ");
00125 
00126   delete fKey;
00127   fKey = 0;
00128   fIndexKeys.clear();
00129 
00130 }

Member Function Documentation

void TDbiResultSet::BuildLookUpTable ( ) const [protected]

Definition at line 133 of file TDbiResultSet.cxx.

References fIndexKeys, TDbiTableRow::GetAggregateNo(), TDbiTableRow::GetIndex(), GetNumRows(), TDbiTableRow::GetOwner(), TDbiValidityRec::GetSeqNo(), GetTableRow(), GetTableRowByIndex(), GetValidityRec(), IsExtendedContext(), SK_DBI_Severe, SK_DBI_Verbose, and TableName().

Referenced by TDbiResultSetNonAgg::GetTableRowByIndex(), and TDbiResultSetNonAgg::Streamer().

00133                                            {
00134 //
00135 //
00136 //  Purpose:  Build look-up Natural Index -> TableRow.
00137 //
00138 //  Contact:   N. West
00139 //
00140 //  Program Notes:-
00141 //  =============
00142 //
00143 //  This member function assumes that the sub-class can support
00144 //  the GetTableRow(...) and GetNumRows methods so take care if
00145 //  called in the sub-class ctor.
00146 
00147 //  Extended Context serach can produce duplicates.
00148   Bool_t duplicatesOK = this->IsExtendedContext();
00149 
00150   SK_DBI_Verbose( "Building look-uptable. Allow duplicates: "
00151                             << duplicatesOK << "  ");
00152 
00153   for ( Int_t rowNo = this->GetNumRows()-1;
00154         rowNo >= 0;
00155         --rowNo ) {
00156     const TDbiTableRow* row  = this->GetTableRow(rowNo);
00157     UInt_t index            = row->GetIndex(rowNo);
00158 //  Ensure we use this class's GetTableRowByIndex, the method is
00159 //  virtual but if the subclass has called this method then it must
00160 //  be the right one to use. [Actually TDbiResultSetAgg overrides
00161 //  GetTableRowByIndex, but only to make building lazy].
00162     const TDbiTableRow* row2 = this->TDbiResultSet::GetTableRowByIndex(index);
00163 
00164     SK_DBI_Verbose(  "Look-up. Row no " << rowNo
00165           << " index " << index
00166           << " row,row2 " << (void*) row << "," << (void*) row2 << "  ");
00167 
00168     if ( row2 != 0 && row2 != row && ! duplicatesOK ) {
00169       std::ostringstream msg;
00170       msg << "Duplicated row natural index: " << index
00171           << " Found at row " <<  rowNo
00172           << " of table " <<  this->TableName()
00173           << ":-\n     index of agg " <<  row->GetAggregateNo();
00174       if ( row->GetOwner() ) msg << "(SEQNO " << row->GetOwner()->GetValidityRec(row).GetSeqNo() << ")";
00175       msg << " matches agg " <<  row2->GetAggregateNo();
00176       if ( row2->GetOwner() ) msg << "(SEQNO " << row2->GetOwner()->GetValidityRec(row2).GetSeqNo() << ")";
00177          SK_DBI_Severe( msg.str() << "  ");
00178    }
00179 
00180     else  fIndexKeys[index] = row;
00181   }
00182 
00183 }

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Bool_t TDbiResultSet::CanDelete ( const TDbiResultSet * res = 0 ) [virtual]

Return true if no clients and unlikely to be reused.

Definition at line 187 of file TDbiResultSet.cxx.

References CanReuse(), GetNumClients(), GetValidityRec(), and SetCanReuse().

Referenced by TDbiCache::Purge().

00187                                                         {
00188 //
00189 //
00190 //  Purpose:  See if suitable for deleting.
00191 //
00192 //  Arguments:
00193 //    res          in    A TDbiResultSet that is currently used.
00194 //                       Optional: default = 0.
00195 
00196 //  If the query would be satisfied apart from the date, then
00197 //  assume we have moved out of the validity window, never
00198 //  to return!
00199 
00200   if (     res
00201         && this->CanReuse()
00202         && this->GetValidityRec().HasExpired(res->GetValidityRec())
00203      )  this->SetCanReuse(kFALSE);
00204 
00205   return ! this->GetNumClients() && ! this->CanReuse();
00206 }

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virtual Bool_t TDbiResultSet::CanReuse ( ) const [inline, virtual]

Definition at line 62 of file TDbiResultSet.hxx.

References fCanReuse.

Referenced by CanDelete(), TDbiResultSetNonAgg::Satisfies(), TDbiResultSetAgg::Satisfies(), and Satisfies().

00062 { return fCanReuse; }

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virtual Bool_t TDbiResultSet::CanSave ( ) const [inline, virtual]

Definition at line 63 of file TDbiResultSet.hxx.

Referenced by TDbiTableProxy::SaveToL2Cache().

00063 { return kTRUE; }

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void TDbiResultSet::CaptureExceptionLog ( UInt_t startFrom )

Definition at line 210 of file TDbiResultSet.cxx.

References TDbiExceptionLog::Clear(), TDbiExceptionLog::Copy(), fExceptionLog, and TDbiExceptionLog::GetGELog().

Referenced by TDbiTableProxy::Query().

00210                                                         {
00211 //
00212 //
00213 //  Purpose: Capture Exception Log from latest entries in Global Exception Log.
00214 
00215   fExceptionLog.Clear();
00216   TDbiExceptionLog::GetGELog().Copy(fExceptionLog,startFrom);
00217 
00218 }

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virtual void TDbiResultSet::Connect ( ) const [inline, virtual]

Definition at line 64 of file TDbiResultSet.hxx.

References fNumClients.

00064 { ++fNumClients; }

virtual TDbiResultKey* TDbiResultSet::CreateKey ( ) const [pure virtual]

Implemented in TDbiResultSetAgg, and TDbiResultSetNonAgg.

Referenced by TDbiResultSetAgg::CreateKey(), and GenerateKey().

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virtual void TDbiResultSet::Disconnect ( ) const [inline, virtual]

Definition at line 66 of file TDbiResultSet.hxx.

References fNumClients.

00066 { --fNumClients; }

void TDbiResultSet::GenerateKey ( ) [virtual]

Key handling.

Definition at line 222 of file TDbiResultSet.cxx.

References CreateKey(), fKey, and GetNumRows().

Referenced by TDbiCache::Adopt().

00222                                 {
00223 //
00224 //
00225 //  Purpose: Create key if set not empty and not already done.
00226 
00227   if ( fKey || this->GetNumRows() == 0) return;
00228   fKey = this->CreateKey();
00229 
00230 }

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const TDbiExceptionLog& TDbiResultSet::GetExceptionLog ( ) const [inline]

Definition at line 67 of file TDbiResultSet.hxx.

References fExceptionLog.

00067 { return fExceptionLog; }

Int_t TDbiResultSet::GetID ( ) const [inline]

Definition at line 68 of file TDbiResultSet.hxx.

References fID.

00068 { return fID; }

const TDbiResultKey * TDbiResultSet::GetKey ( ) const [virtual]

Definition at line 234 of file TDbiResultSet.cxx.

References fKey, and TDbiResultKey::GetEmptyKey().

Referenced by TDbiCache::Adopt().

00234                                                  {
00235 
00236 //  Purpose:  Get the associated TDbiResultKey, or an empty one if none exists.
00237 
00238   return fKey ? fKey : TDbiResultKey::GetEmptyKey();
00239 
00240 }

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virtual UInt_t TDbiResultSet::GetNumAggregates ( ) const [pure virtual]

Implemented in TDbiResultSetAgg, and TDbiResultSetNonAgg.

Referenced by TDbiCache::Search().

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virtual UInt_t TDbiResultSet::GetNumClients ( ) const [inline, virtual]

Definition at line 71 of file TDbiResultSet.hxx.

References fNumClients.

Referenced by CanDelete(), TDbiCache::Purge(), and Satisfies().

00071                                                      {
00072                                                    return fNumClients; }

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virtual UInt_t TDbiResultSet::GetNumRows ( ) const [pure virtual]

Implemented in TDbiResultSetAgg, and TDbiResultSetNonAgg.

Referenced by BuildLookUpTable(), GenerateKey(), TDbiValRecSet::GetNumRows(), TDbiTableProxy::SaveToL2Cache(), and TDbiCache::Search().

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const string& TDbiResultSet::GetSqlQualifiers ( ) const [inline]

Definition at line 74 of file TDbiResultSet.hxx.

References fSqlQualifiers.

Referenced by IsExtendedContext(), TDbiResultSetNonAgg::Satisfies(), and TDbiResultSetAgg::Satisfies().

00074 { return fSqlQualifiers; }

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virtual const TDbiTableRow* TDbiResultSet::GetTableRow ( UInt_t rowNum ) const [pure virtual]

Implemented in TDbiResultSetAgg, and TDbiResultSetNonAgg.

Referenced by BuildLookUpTable(), and TDbiValRecSet::GetTableRow().

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const TDbiTableRow * TDbiResultSet::GetTableRowByIndex ( UInt_t index ) const [virtual]

Reimplemented in TDbiResultSetNonAgg.

Definition at line 244 of file TDbiResultSet.cxx.

References fIndexKeys.

Referenced by BuildLookUpTable().

00244                                                                         {
00245 //
00246 //
00247 //  Purpose:  Return row corresponding to Natural Index (or 0 if none)
00248 //
00249 //  Contact:   N. West
00250 //
00251 
00252 // Use Find rather than operator[] to avoid creating entry
00253 // if index missing
00254   IndexToRow_t::const_iterator idx = fIndexKeys.find(index);
00255   return ( idx == fIndexKeys.end() ) ? 0 : (*idx).second;
00256 
00257 }

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virtual const TDbiValidityRec& TDbiResultSet::GetValidityRec ( const TDbiTableRow * = 0 ) const [inline, virtual]

Reimplemented in TDbiResultSetAgg.

Definition at line 77 of file TDbiResultSet.hxx.

References GetValidityRecGlobal().

Referenced by TDbiCache::Adopt(), BuildLookUpTable(), CanDelete(), TDbiResultSetNonAgg::CreateKey(), TDbiResultSetAgg::CreateKey(), TDbiCache::Purge(), TDbiTableProxy::RestoreFromL2Cache(), TDbiResultSetNonAgg::Satisfies(), and Satisfies().

00078                                                                            {
00079                                         return GetValidityRecGlobal(); }

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virtual const TDbiValidityRec& TDbiResultSet::GetValidityRecGlobal ( ) const [inline, virtual]

Definition at line 80 of file TDbiResultSet.hxx.

References fEffVRec.

Referenced by TDbiCache::Adopt(), TDbiResultSetAgg::GetValidityRec(), GetValidityRec(), and TDbiResultSetAgg::Streamer().

00080                                                              {
00081                                                       return fEffVRec; }

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Bool_t TDbiResultSet::IsExtendedContext ( ) const [inline]

Definition at line 82 of file TDbiResultSet.hxx.

References GetSqlQualifiers().

Referenced by BuildLookUpTable(), and Satisfies().

00082                                                          {
00083                                        return this->GetSqlQualifiers() != ""; }

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Bool_t TDbiResultSet::LookUpBuilt ( ) const [inline, protected]

Definition at line 116 of file TDbiResultSet.hxx.

References fIndexKeys.

Referenced by TDbiResultSetNonAgg::GetTableRowByIndex().

00116 { return fIndexKeys.size() > 0; }

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virtual Bool_t TDbiResultSet::Owns ( const TDbiTableRow * ) const [inline, virtual]

Reimplemented in TDbiResultSetNonAgg.

Definition at line 84 of file TDbiResultSet.hxx.

00084 { return kFALSE; }

Bool_t TDbiResultSet::ResultsFromDb ( ) const [inline]

Definition at line 85 of file TDbiResultSet.hxx.

References fResultsFromDb.

Referenced by TDbiTableProxy::SaveToL2Cache().

00085 { return fResultsFromDb; }

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virtual Bool_t TDbiResultSet::Satisfies	(	const TDbiValidityRec &	,
		const string &	= `""`
	)			`[inline, virtual]`

Reimplemented in TDbiResultSetNonAgg.

Definition at line 101 of file TDbiResultSet.hxx.

00102                                                  {return kFALSE;}

virtual Bool_t TDbiResultSet::Satisfies ( const string & ) [inline, virtual]

Not all TDbiResultSet classes can satisfy these types of query so those that do must override.

Reimplemented in TDbiResultSetAgg.

Definition at line 100 of file TDbiResultSet.hxx.

00100 {return kFALSE;}

Bool_t TDbiResultSet::Satisfies	(	const TVldContext &	vc,
		const TDbi::Task &	task
	)			`[virtual]`

All TDbiResultSet classes can satisfy this type of primary query so impliment here.

Definition at line 261 of file TDbiResultSet.cxx.

References CanReuse(), GetNumClients(), GetValidityRec(), TDbiValidityRec::HasExpired(), TDbiValidityRec::IsCompatible(), IsExtendedContext(), SetCanReuse(), and SK_DBI_Debug.

Referenced by TDbiCache::Search().

00262                                                   {
00263 //
00264 //
00265 //  Purpose:  Check to see if this Result satisfies specific context query.
00266 //
00267 //  Arguments:
00268 //    vc           in    Context of query
00269 //    task         in    Task of query
00270 //
00271 //  Return:    kTRUE if can satisfy query.
00272 //
00273 //  Contact:   N. West
00274 //
00275 //  Program Notes:-
00276 //  =============
00277 
00278 //  If it cannot satisfy the query in a way that suggests
00279 //  that its unlikely that it will satisfy future queries
00280 //  then mark as cannot reuse so that it becomes eligible
00281 //  for purging.
00282 
00283 // Extended Context queries cannot satisfy specific context queries.
00284 
00285   Bool_t isExtendedContext = this->IsExtendedContext();
00286   Bool_t canReuse          = this->CanReuse();
00287   Bool_t isCompatible      = this->GetValidityRec().IsCompatible(vc,task);
00288   Bool_t hasExpired        = this->GetValidityRec().HasExpired(vc,task);
00289   UInt_t numClients        = this->GetNumClients();
00290   SK_DBI_Debug(  "    Checking result with TDbiValidityRec:- \n      " << this->GetValidityRec()
00291     << "  With extended context: " << isExtendedContext
00292     << " CanReuse: " << canReuse
00293     << " Is Compatible: " << isCompatible
00294     << " HasExpired: " <<  hasExpired
00295     << " number of clients: " << numClients
00296     << "  ");
00297 
00298   if ( isExtendedContext ) return kFALSE;
00299 
00300   if ( canReuse && isCompatible )  return kTRUE;
00301 
00302 //  If the query would be satisfied apart from the date, then
00303 //  assume we have moved out of the validity window, never
00304 //  to return!
00305 
00306   if ( canReuse && hasExpired && numClients == 0 )  {
00307     SK_DBI_Debug( "    Marking result as not reusable" << "  ");
00308    this-> SetCanReuse(kFALSE);
00309   }
00310 
00311   return kFALSE;
00312 
00313 }

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virtual void TDbiResultSet::SetCanReuse ( Bool_t reuse ) [inline, virtual]

Definition at line 108 of file TDbiResultSet.hxx.

References fCanReuse.

Referenced by CanDelete(), TDbiTableProxy::Query(), and Satisfies().

00108 { fCanReuse = reuse ; }

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void TDbiResultSet::SetResultsFromDb ( ) [inline, protected]

Definition at line 111 of file TDbiResultSet.hxx.

References fResultsFromDb.

00111 { fResultsFromDb = kTRUE; }

virtual void TDbiResultSet::SetTableName ( const string & tableName ) [inline, protected, virtual]

Definition at line 120 of file TDbiResultSet.hxx.

References fTableName.

00120                                                      {
00121                                                fTableName = tableName; }

virtual void TDbiResultSet::SetValidityRec ( const TDbiValidityRec & vRec ) [inline, protected, virtual]

Definition at line 122 of file TDbiResultSet.hxx.

References fEffVRec.

00122                                                            {
00123                                                       fEffVRec = vRec; }

void TDbiResultSet::Streamer ( TDbiBinaryFile & file ) [virtual]

Reimplemented in TDbiResultSetAgg, and TDbiResultSetNonAgg.

Definition at line 316 of file TDbiResultSet.cxx.

References fCanReuse, fEffVRec, fNumClients, fResultsFromDb, fTableName, TDbiBinaryFile::IsReading(), TDbiBinaryFile::IsWriting(), SK_DBI_Debug, SK_DBI_Verbose, and TDbiValidityRec::Streamer().

Referenced by operator<<(), and operator>>().

00316                                                  {
00317 //
00318 //
00319 //  Purpose:  I/O to binary file
00320 //
00321 //  Program Notes:-
00322 //  =============
00323 
00324 //  Don't store fIndexKeys; it will be rebuilt on input by the subclass.
00325 
00326   if ( file.IsReading() ) {
00327     SK_DBI_Debug( "    Restoring TDbiResultSet ..." << "  ");
00328     file >> fCanReuse;
00329     fEffVRec.Streamer(file);
00330     SK_DBI_Verbose( "    Restored " << fEffVRec << "  ");
00331     fResultsFromDb = kFALSE;
00332     fNumClients    = 0;
00333     file >> fTableName;
00334     SK_DBI_Verbose( "    Restored string " << fTableName << "  ");
00335   }
00336   else if ( file.IsWriting() ) {
00337     SK_DBI_Debug( "    Saving TDbiResultSet ..." << "  ");
00338     file << fCanReuse;
00339     SK_DBI_Verbose( "    Saving " << fEffVRec << "  ");
00340     fEffVRec.Streamer(file);
00341     SK_DBI_Verbose( "    Saving string " << fTableName << "  ");
00342     file << fTableName;
00343   }
00344 }