Drawings SDK Developer Guide > Working with .dwg Files > Working with Entities > Working with Specific Entitites > Working with Tables > Link Tables to Excel Spreadsheet Data
Link Tables to Excel Spreadsheet Data

With ODA Drawings SDK you are able to link table data with an external Microsoft® Excel spreadsheet.

These are the main classes that provide the table linkage functionality:

  • OdDbDataLink — Represents a connection from an OdDbTable object to external table data.
  • OdDbDataLinkManager — Provides functionality for creating, storing and managing data link objects in the database.
  • OdDbLinkedData — Provides methods for working with the structure and content of the linked table data, such as adding and removing rows and columns, creating and removing content of a specific cell etc.

The paragraphs below describes how to use this functionality to enable interoperability of a table in a .dwg drawing and an external Excel file.

Get Data Link Manager

To establish a connection to external table data, get an instance of the OdDbDataLinkManager class, which creates and manages all the data links for the database. To get the data link manager for a specific database, use the global odDbGetDataLinkManager(OdDbDatabase* db) function:

OdDbDataLinkManager* dataLinkManager = odDbGetDataLinkManager(pDb); 

The function returns the already existing OdDbDataLinkManager object or creates one if it doesn't exist.

Create, Get or Remove Data Links

Once you get the OdDbDataLinkManager object, you are able to create connections to external data. A connection is represented by an OdDbDataLink object, which can be created using the OdDbDataLinkManager::createDataLink() method. The method has the following signatures:

OdDbObjectId OdDbDataLinkManager::createDataLink(const OdString& adapterId, const OdString& name, const OdString& description, const OdString& connectionString)

The method creates an OdDbDataLink object with specified parameters, puts it to the data link dictionary with the specified name and returns the ObjectID.

You can get the total number of created OdDbDataLink objects using the OdDbDataLinkManager::dataLinkCount() method.

To get existing OdDbDataLink objects, OdDbDataLinkManager class provides the getDataLink() method with the following signatures:

  • To get an OdDbDataLink object by its name, use either:

    • OdDbObjectId OdDbDataLinkManager::getDataLink(const OdString& name);
    • OdDbDataLinkPtr OdDbDataLinkManager::getDataLink(const OdString& name, OdDb::OpenMode mode);
  • To get all existing OdDbDataLink objects, use:

    int OdDbDataLinkManager::getDataLink(OdDbObjectIdArray& dataLinks);

    The method gets an array of data links and returns the total number of links in the database.

Removing data links is performed by the removeDataLink() method implemented in two signatures:

  • To remove a OdDbDataLink object from the data link dictionary by its ID, use void removeDataLink(const OdDbObjectId& idDataLink);
  • To remove a data link with specific name, use void removeDataLink(const OdString& sKey, OdDbObjectId& idDataLink);. ID of the removed object is stored in the idDataLink parameter.

Link the Table with External Data

After a data link is created, you can link the table with the external table data. Set the link to table data for a specific cell or a cells range using the OdDbTable::setDataLink() methods:

  • void OdDbTable::setDataLink (OdInt32 row, OdInt32 col, const OdDbObjectId& idDataLink, bool bUpdate);
  • void OdDbTable::setDataLink (const OdCellRange& range, const OdDbObjectId& idDataLink, bool bUpdate);

The bUpdate flag indicates if the data link is to be updated after it's set.

To get a data link set for a table cell or a cells range, use the OdDbTable::getDataLink () methods:

  • OdDbObjectId getDataLink (OdInt32 row, OdInt32 col) const;
  • OdInt32 getDataLink (const OdCellRange& pRange, OdDbObjectIdArray& dataLinkIds) const;
  • OdDbDataLinkPtr getDataLink (OdInt32 row, OdInt32 col, OdDb::OpenMode mode) const;

Update the Link Data

For linked tables, you can use the OdDbTable::updateDataLink() methods to upload data from your table to the source excel data or download the changes from the source table:

  • void updateDataLink (OdInt32 row, OdInt32 col, OdDb::UpdateDirection nDir, OdDb::UpdateOption nOption);
  • void updateDataLink (OdDb::UpdateDirection nDir, OdDb::UpdateOption nOption);

To update the table with downloading data from the source table, use OdDB::kUpdateDirectionSourceToData as an nDir value.

To update the source table with uploading data from your table, use OdDB::kUpdateDirectionDataToSource as an nDir value.

Sample Code

Sample code of the CreateLinkedTable command for creating a linked table is available in Drawing\Examples\ExCustObjs\DrxDebugCmds.cpp

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