C++ QSqlIndex::count方法代码示例

void tst_QSqlDriver::primaryIndex()
{
    QFETCH_GLOBAL(QString, dbName);
    QSqlDatabase db = QSqlDatabase::database(dbName);
    CHECK_DATABASE(db);

    QString tablename(qTableName("relTEST1", __FILE__));
    //check that we can get primary index using unquoted mixed case table name
    QSqlIndex index = db.driver()->primaryIndex(tablename);
    QCOMPARE(index.count(), 1);

    if( db.driverName().startsWith("QIBASE") || db.driverName().startsWith("QOCI") || db.driverName().startsWith("QDB2"))
        QCOMPARE(index.fieldName(0), QString::fromLatin1("ID"));
    else
        QCOMPARE(index.fieldName(0), QString::fromLatin1("id"));


    //check that we can get the primary index using a quoted tablename
    if( db.driverName().startsWith("QIBASE") || db.driverName().startsWith("QOCI") || db.driverName().startsWith("QDB2"))
        tablename = tablename.toUpper();
    else if (db.driverName().startsWith("QPSQL"))
        tablename = tablename.toLower();

    if(!db.driverName().startsWith("QODBC") && !db.databaseName().contains("PostgreSql")) {
        index = db.driver()->primaryIndex(db.driver()->escapeIdentifier(tablename, QSqlDriver::TableName));
        QCOMPARE(index.count(), 1);
    }
    if( db.driverName().startsWith("QIBASE") || db.driverName().startsWith("QOCI") || db.driverName().startsWith("QDB2"))
        QCOMPARE(index.fieldName(0), QString::fromLatin1("ID"));
    else
        QCOMPARE(index.fieldName(0), QString::fromLatin1("id"));



    //check that we can not get the primary index using a quoted but incorrect table name casing
    if( db.driverName().startsWith("QIBASE") || db.driverName().startsWith("QOCI") || db.driverName().startsWith("QDB2"))
        tablename = tablename.toLower();
    else if (db.driverName().startsWith("QPSQL"))
        tablename = tablename.toUpper();

    index = db.driver()->primaryIndex(db.driver()->escapeIdentifier(tablename, QSqlDriver::TableName));
    if (tst_Databases::isMySQL(db)
      || db.driverName().startsWith("QSQLITE")
      || db.driverName().startsWith("QTDS")
      || tst_Databases::isSqlServer(db)
      || tst_Databases::isMSAccess(db))
        QCOMPARE(index.count(), 1); //mysql will always find the table name regardless of casing
    else
        QCOMPARE(index.count(), 0);
}

QString qOrderByClause( const QSqlIndex & i, const QString& prefix = QString::null )
{
    QString str;
    int k = i.count();
    if( k == 0 ) return QString::null;
    str = " order by " + i.toString( prefix );
    return str;
}

QString qOrderByClause(const QSqlIndex & i, const QString& prefix = QString())
{
    QString str;
    int k = i.count();
    if(k == 0)
        return QString();
    str = QLatin1String(" order by ") + i.toString(prefix);
    return str;
}

QString getPrimary(QSqlDatabase &db, QString sTable)
{
  QString sPrimary = "kbrecordid";

  QSqlIndex i = db.driver()->primaryIndex(sTable);
  if (i.count()){
    sPrimary = i.fieldName(0);
  }
  return sPrimary;
}

static bool index_matches(const Q3SqlCursor* cur, const QSqlRecord* buf,
                           const QSqlIndex& idx)
{
    bool indexEquals = false;
    for (int i = 0; i < idx.count(); ++i) {
        const QString fn(idx.field(i).name());
        if (cur->value(fn) == buf->value(fn))
            indexEquals = true;
        else {
            indexEquals = false;
            break;
        }
    }
    return indexEquals;
}

bool Q3SqlCursor::select(const QString & filter, const QSqlIndex & sort)
{
    QString fieldList(toString(d->nm));
    if (fieldList.isEmpty())
        return false;
    QString str(QLatin1String("select ") + fieldList);
    str += QLatin1String(" from ") + d->nm;
    if (!filter.isEmpty()) {
        d->ftr = filter;
        str += QLatin1String(" where ") + filter;
    } else
        d->ftr.clear();
    if (sort.count() > 0)
        str += QLatin1String(" order by ") + sort.toString(d->nm);
    d->srt = sort;
    return exec(str);
}

bool QSqlCursor::select( const QString & filter, const QSqlIndex & sort )
{
    QString fieldList = toString( d->nm );
    if ( fieldList.isEmpty() )
	return FALSE;
    QString str= "select " + fieldList;
    str += " from " + d->nm;
    if ( !filter.isEmpty() ) {
	d->ftr = filter;
	str += " where " + filter;
    } else
	d->ftr = QString::null;
    if ( sort.count() > 0 )
	str += " order by " + sort.toString( d->nm );
    d->srt = sort;
    return exec( str );
}

QString Q3SqlCursor::toString(const QSqlIndex& i, QSqlRecord* rec, const QString& prefix,
                                const QString& fieldSep, const QString& sep) const
{
    QString filter;
    bool separator = false;
    for(int j = 0; j < i.count(); ++j){
        if (rec->isGenerated(j)) {
            if(separator) {
                filter += QLatin1Char(' ') + sep + QLatin1Char(' ') ;
            }
            QString fn = i.fieldName(j);
            QSqlField f = rec->field(fn);
            filter += toString(prefix, &f, fieldSep);
            separator = true;
        }
    }
    return filter;
}

QString QSqlCursor::toString( const QSqlIndex& i, QSqlRecord* rec, const QString& prefix,
				const QString& fieldSep, const QString& sep ) const
{
    QString filter;
    bool separator = FALSE;
    for( uint j = 0; j < i.count(); ++j ){
	if ( rec->isGenerated( j ) ) {
	    if( separator ) {
		filter += " " + sep + " " ;
	    }
	    QString fn = i.fieldName( j );
	    QSqlField* f = rec->field( fn );
	    filter += toString( prefix, f, fieldSep );
	    separator = TRUE;
	}
    }
    return filter;
}

//## possibly add sizeHint parameter
bool Q3SqlCursorManager::findBuffer(const QSqlIndex& idx, int atHint)
{
#ifdef QT_DEBUG_DATAMANAGER
    qDebug("Q3SqlCursorManager::findBuffer:");
#endif
    Q3SqlCursor* cur = cursor();
    if (!cur)
        return false;
    if (!cur->isActive())
        return false;
    if (!idx.count()) {
        if (cur->at() == QSql::BeforeFirst)
            cur->next();
        return false;
    }
    QSqlRecord* buf = cur->editBuffer();
    bool indexEquals = false;
#ifdef QT_DEBUG_DATAMANAGER
    qDebug(" Checking hint...");
#endif
    /* check the hint */
    if (cur->seek(atHint))
        indexEquals = index_matches(cur, buf, idx);

    if (!indexEquals) {
#ifdef QT_DEBUG_DATAMANAGER
        qDebug(" Checking current page...");
#endif
        /* check current page */
        int pageSize = 20;
        int startIdx = qMax(atHint - pageSize, 0);
        int endIdx = atHint + pageSize;
        for (int j = startIdx; j <= endIdx; ++j) {
            if (cur->seek(j)) {
                indexEquals = index_matches(cur, buf, idx);
                if (indexEquals)
                    break;
            }
        }
    }

    if (!indexEquals && cur->driver()->hasFeature(QSqlDriver::QuerySize)
         && cur->sort().count()) {
#ifdef QT_DEBUG_DATAMANAGER
        qDebug(" Using binary search...");
#endif
        // binary search based on record buffer and current sort fields
        int lo = 0;
        int hi = cur->size();
        int mid;
        if (compare_recs(buf, cur, cur->sort()) >= 0)
            lo = cur->at();
        while (lo != hi) {
            mid = lo + (hi - lo) / 2;
            if (!cur->seek(mid))
                break;
            if (index_matches(cur, buf, idx)) {
                indexEquals = true;
                break;
            }
            int c = compare_recs(buf, cur, cur->sort());
            if (c < 0) {
                hi = mid;
            } else if (c == 0) {
                // found it, but there may be duplicates
                int at = mid;
                do {
                    mid--;
                    if (!cur->seek(mid))
                        break;
                    if (index_matches(cur, buf, idx)) {
                        indexEquals = true;
                        break;
                    }
                } while (compare_recs(buf, cur, cur->sort()) == 0);

                if (!indexEquals) {
                    mid = at;
                    do {
                        mid++;
                        if (!cur->seek(mid))
                            break;
                        if (index_matches(cur, buf, idx)) {
                            indexEquals = true;
                            break;
                        }
                    } while (compare_recs(buf, cur, cur->sort()) == 0);
                }
                break;
            } else if (c > 0) {
                lo = mid + 1;
            }
        }
    }

    if (!indexEquals) {
#ifdef QT_DEBUG_DATAMANAGER
        qDebug(" Using brute search...");
#endif
//.........这里部分代码省略.........

bool QgsDb2GeometryColumns::populateLayerProperty( QgsDb2LayerProperty &layer )
{
  if ( !mQuery.isActive() || !mQuery.next() )
  {
    return false;
  }

  layer.schemaName = mQuery.value( 0 ).toString().trimmed();
  layer.tableName = mQuery.value( 1 ).toString().trimmed();
  layer.geometryColName = mQuery.value( 2 ).toString().trimmed();
  layer.type = mQuery.value( 3 ).toString();
  if ( mQuery.value( 4 ).isNull() )
  {
    layer.srid.clear();
    layer.srsName.clear();
  }
  else
  {
    layer.srid = mQuery.value( 4 ).toString();
    layer.srsName = mQuery.value( 5 ).toString();
  }
  layer.extents = QStringLiteral( "0 0 0 0" ); // no extents
  if ( ENV_LUW == mEnvironment )
  {
    if ( !mQuery.value( 6 ).isNull() ) // Don't get values if null
    {
      layer.extents = QString(
                        mQuery.value( 6 ).toString() + ' ' +
                        mQuery.value( 7 ).toString() + ' ' +
                        mQuery.value( 8 ).toString() + ' ' +
                        mQuery.value( 9 ).toString() ).trimmed();
    }
  }
  QgsDebugMsg( QStringLiteral( "layer: %1.%2(%3) type='%4' srid='%5' srsName='%6'" )
               .arg( layer.schemaName, layer.tableName, layer.geometryColName,
                     layer.type, layer.srid, layer.srsName ) );
  QgsDebugMsg( "Extents: '" + layer.extents + "'" );

  layer.pkCols = QStringList();

  // Use the Qt functionality to get the primary key information
  // to set the FID column.
  // We can only use the primary key if it only has one column and
  // the type is Integer or BigInt.
  QString table = QStringLiteral( "%1.%2" ).arg( layer.schemaName, layer.tableName );
  QSqlIndex pk = mDatabase.primaryIndex( table );
  if ( pk.count() == 1 )
  {
    QSqlField pkFld = pk.field( 0 );
    QVariant::Type pkType = pkFld.type();
    if ( ( pkType == QVariant::Int ||  pkType == QVariant::LongLong ) )
    {
      QString fidColName = pk.fieldName( 0 );
      layer.pkCols.append( fidColName );
      QgsDebugMsg( "pk is: " + fidColName );
    }
  }
  else
  {
    QgsDebugMsg( "Warning: table primary key count is " + QString::number( pk.count() ) );
  }
  layer.pkColumnName = layer.pkCols.size() > 0 ? layer.pkCols.at( 0 ) : QString();
  return true;
}