syscolumnsrowfactory.java

derby database source code.good for you.

	 * Builds an empty index row.
	 *
	 *	@param	indexNumber	Index to build empty row for.
	 *  @param  rowLocation	Row location for last column of index row
	 *
	 * @return corresponding empty index row
	 * @exception   StandardException thrown on failure
	 */
	public ExecIndexRow	buildEmptyIndexRow( int indexNumber,
											RowLocation rowLocation) 
			throws StandardException
	{
		int ncols = getIndexColumnCount(indexNumber);
		ExecIndexRow row = getExecutionFactory().getIndexableRow(ncols + 1);

		row.setColumn(ncols + 1, rowLocation);

		switch(indexNumber)
		{
			case SYSCOLUMNS_INDEX1_ID:
				/* 1st column is REFERENCEID (UUID - char(36)) */
				row.setColumn
					(1, getDataValueFactory().getCharDataValue((String) null));

				/* 2nd column is COLUMNNAME (varchar(128)) */
				row.setColumn
				    (2, 
					 getDataValueFactory().getVarcharDataValue((String) null));

				break;

		    case SYSCOLUMNS_INDEX2_ID:
				
				/* 1st column is DEFAULTID (UUID - char(36)) */
				row.setColumn
					(1, getDataValueFactory().getCharDataValue((String) null));

				break;
		}	// end switch

		return	row;
	}


	/**
	 * Make a ColumnDescriptor out of a SYSCOLUMNS row
	 *
	 * @param row 					a SYSCOLUMNS row
	 * @param parentTupleDescriptor	The UniqueTupleDescriptor for the object that is tied
	 *								to this column
	 * @param dd 					dataDictionary
	 *
	 * @return	a column descriptor equivalent to a SYSCOLUMNS row
	 *
	 * @exception   StandardException thrown on failure
	 */
	public TupleDescriptor buildDescriptor(
		ExecRow					row,
		TupleDescriptor			parentTupleDescriptor,
		DataDictionary 			dd )
					throws StandardException
	{
		if (SanityManager.DEBUG)
		{
			SanityManager.ASSERT(row.nColumns() == SYSCOLUMNS_COLUMN_COUNT, 
								 "Wrong number of columns for a SYSCOLUMNS row");
		}

		int columnNumber;
		String columnName;
		String defaultID;
		DefaultInfoImpl		defaultInfo = null;
		ColumnDescriptor colDesc;
		BaseTypeIdImpl		typeId;
		TypeId	wrapperTypeId;
		DataValueDescriptor	defaultValue = null;
		UUID				defaultUUID = null;
		UUID				uuid = null;
		UUIDFactory			uuidFactory = getUUIDFactory();
		long autoincStart, autoincInc;

		DataDescriptorGenerator	ddg = dd.getDataDescriptorGenerator();


		/*
		** We're going to be getting the UUID for this sucka
		** so make sure it is a UniqueTupleDescriptor.
		*/
		if (parentTupleDescriptor != null)
		{
			if (SanityManager.DEBUG)
			{
				if (!(parentTupleDescriptor instanceof UniqueTupleDescriptor))
				{
					SanityManager.THROWASSERT(parentTupleDescriptor.getClass().getName() 
							+ " not instanceof UniqueTupleDescriptor");	
				}
			}
			uuid = ((UniqueTupleDescriptor)parentTupleDescriptor).getUUID();
		}
		else
		{
			/* 1st column is REFERENCEID (char(36)) */
			uuid = uuidFactory.recreateUUID(row.getColumn(SYSCOLUMNS_REFERENCEID).
													getString());
		}

		/* NOTE: We get columns 5 and 6 next in order to work around 
		 * a 1.3.0 HotSpot bug.  (#4361550)
		 */

		// 5th column is COLUMNDEFAULT (serialiazable)
		Object object = row.getColumn(SYSCOLUMNS_COLUMNDEFAULT).getObject();
		if (object instanceof DataValueDescriptor)
		{
			defaultValue = (DataValueDescriptor) object;
		}
		else if (object instanceof DefaultInfoImpl)
		{
			defaultInfo = (DefaultInfoImpl) object;
			defaultValue = defaultInfo.getDefaultValue();
		}

		/* 6th column is DEFAULTID (char(36)) */
		defaultID = row.getColumn(SYSCOLUMNS_COLUMNDEFAULTID).getString();

		if (defaultID != null)
		{
			defaultUUID = uuidFactory.recreateUUID(defaultID);
		}

		/* 2nd column is COLUMNNAME (varchar(128)) */
		columnName = row.getColumn(SYSCOLUMNS_COLUMNNAME).getString();

		/* 3rd column is COLUMNNUMBER (int) */
		columnNumber = row.getColumn(SYSCOLUMNS_COLUMNNUMBER).getInt();

		/* 4th column is COLUMNDATATYPE */

		/*
		** What is stored in the column is a TypeDescriptorImpl, which
		** points to a BaseTypeIdImpl.  These are simple types that are
		** intended to be movable to the client, so they don't have
		** the entire implementation.  We need to wrap them in DataTypeServices
		** and TypeId objects that contain the full implementations for
		** language processing.
		*/
		TypeDescriptorImpl typeDescriptor = (TypeDescriptorImpl) row.getColumn(SYSCOLUMNS_COLUMNDATATYPE).
													getObject();
		typeId = typeDescriptor.getTypeId();

		/*
		** The BaseTypeIdImpl tells what type of TypeId it is supposed to
		** be wrapped in.
		*/
		wrapperTypeId =
			(TypeId) Monitor.newInstanceFromIdentifier(typeId.wrapperTypeFormatId());
		/* Wrap the BaseTypeIdImpl in a full type id */
		wrapperTypeId.setNestedTypeId(typeId);

		/* Wrap the TypeDescriptorImpl in a full DataTypeDescriptor */
		DataTypeDescriptor dataTypeServices = new DataTypeDescriptor(typeDescriptor,
													wrapperTypeId);

		/* 7th column is AUTOINCREMENTVALUE, not cached in descriptor (long) */

		/* 8th column is AUTOINCREMENTSTART (long) */
		autoincStart = row.getColumn(SYSCOLUMNS_AUTOINCREMENTSTART).getLong();

		/* 9th column is AUTOINCREMENTINC (long) */
		autoincInc = row.getColumn(SYSCOLUMNS_AUTOINCREMENTINC).getLong();

		DataValueDescriptor col = row.getColumn(SYSCOLUMNS_AUTOINCREMENTSTART);
		autoincStart = col.getLong();

		col = row.getColumn(SYSCOLUMNS_AUTOINCREMENTINC);
		autoincInc = col.getLong();

		colDesc = new ColumnDescriptor(columnName, columnNumber,
							dataTypeServices, defaultValue, defaultInfo, uuid, 
							defaultUUID, autoincStart, autoincInc);
		return colDesc;
	}

	/**
	  *	Get the index number for the primary key index on this catalog.
	  *
	  *	@return	a 0-based number
	  *
	  */
	public	int	getPrimaryKeyIndexNumber()
	{
		return SYSCOLUMNS_INDEX1_ID;
	}

	/**
	 * Builds a list of columns suitable for creating this Catalog.
	 *
	 *
	 * @return array of SystemColumn suitable for making this catalog.
	 */
	public SystemColumn[]	buildColumnList()
	{
		if ( columnList != null ) { return columnList; }

		columnList = new SystemColumn[SYSCOLUMNS_COLUMN_COUNT];

		// describe columns

		columnList[0] = 
					new SystemColumnImpl(
								convertIdCase( REFERENCEDID_STRING),			// column name
								SYSCOLUMNS_REFERENCEID,// column number
								0,					// precision
								0,					// scale
								false,				// nullability
								"CHAR",				// dataType
								true,				// built-in type
								36					// maxLength
			                   );

		columnList[1] = 
					new SystemColumnImpl(			// SQL IDENTIFIER
								convertIdCase( COLUMNNAME_STRING),		// column name
								SYSCOLUMNS_COLUMNNAME,	// column number
								false				// nullability
			                   );

		columnList[2] = 
					new SystemColumnImpl(
								convertIdCase( "COLUMNNUMBER"),	// column name
								SYSCOLUMNS_COLUMNNUMBER,	// column number
								0,					// precision
								0,					// scale
								false,				// nullability
								"INTEGER",				// dataType
								true,				// built-in type
								4					// maxLength
							   );

		columnList[3] = 
					new SystemColumnImpl(	
							convertIdCase( "COLUMNDATATYPE"),			// column name
							SYSCOLUMNS_COLUMNDATATYPE,	// column number
							0,					// precision
							0,					// scale
							false,				// nullability
							"org.apache.derby.catalog.TypeDescriptor",	    // dataType
							false,				// built-in type
							TypeDescriptor.MAXIMUM_WIDTH_UNKNOWN // maxLength
			               );

		columnList[4] = 
					new SystemColumnImpl(	
							convertIdCase( "COLUMNDEFAULT"),			// column name
							SYSCOLUMNS_COLUMNDEFAULT,	// column number
							0,					// precision
							0,					// scale
							true,				// nullability
							"java.io.Serializable",	    // dataType
							false,				// built-in type
							TypeDescriptor.MAXIMUM_WIDTH_UNKNOWN // maxLength
			               );

		columnList[5] = 
					new SystemColumnImpl(
								convertIdCase( COLUMNDEFAULTID_STRING),			// column name
								SYSCOLUMNS_COLUMNDEFAULTID,// column number
								0,					// precision
								0,					// scale
								true,				// nullability
								"CHAR",				// dataType
								true,				// built-in type
								36					// maxLength
			                   );

		// new columns for autoincrement.
		columnList[6] = 
			        new SystemColumnImpl(
							    convertIdCase( "AUTOINCREMENTVALUE"), // column name
								SYSCOLUMNS_AUTOINCREMENTVALUE,
								0,
								0, 
								true,
								"BIGINT",
								true,
								TypeId.LONGINT_MAXWIDTH
							   );
		
		columnList[7] = 
			        new SystemColumnImpl(
							    convertIdCase( "AUTOINCREMENTSTART"), // column name
								SYSCOLUMNS_AUTOINCREMENTSTART,
								0,
								0, 
								true,
								"BIGINT",
								true,
								TypeId.LONGINT_MAXWIDTH
							   );

		columnList[8] = 
			        new SystemColumnImpl(
							    convertIdCase( "AUTOINCREMENTINC"), // column name
								SYSCOLUMNS_AUTOINCREMENTINC,
								0,
								0, 
								true,
								"BIGINT",
								true,
								TypeId.LONGINT_MAXWIDTH
							   );

		return	columnList;
	}
}