What is Database linkages? What mean is?

MicroStation and Database Linkages

herovn:

But I don't understand it well.

LIke many Bentley products, the Geo family relies on the MicroStation platform. MicroStation has built-in capability to connect to a relational database (DB) such as Oracle, SQL Server, Access, and others. MicroStation can link (associate) a graphic element with a row in a relational table.

The Geo products make good use of this platform capability to link cartographic geometry (e.g. a property boundary) with its DB data (e.g. information about that property).

This article, although not exhaustive, attempts to explain MicroStation database linkages.

Regards, Jon Summers
LA Solutions

Lets say you have linkages on the centroids of the parcels that refence the parcel table in the database. The parcel table has property values in it. You want to color fill the shapes aroound the parcels, thematically based upoin the parcel value, but there are no linkages on the parcel shapse, just the parcels. You run the associate linakges and effectively 'copy' the linkages from the centroids to the associated shapes. Now you can use the thematic tools to do color fills on the shapes, since they now have the same linkages as the associated centroids.

HTH

Jerry

Jeff.

You give me a specific example, use result of  "Assoation linkages" tool when use in thematic anlysis.

 Thank you very much.

Hero VN

...the "Associate Linkages" tool is used to copy database linkages to/from centroids, boundaries and/or area elements using any of the following modes.

• Centroid -> Shape - copies the database linkages from centroid elements to shape elements.
• Centroid ->Boundary - copies the database linkages from centroid elements to boundaries.
• Shape ->Centroid - copies the database linkages from shapes to centroids.
• Boundary ->Centroid - copies the database linkages from a boundary to its centroid. 

The database linkages themselves can be thought of as non-graphic information (added to your graphic elements) which contain references (ENTITYNUM (table identifier), MSLINK (primary key)) to a database attribute row (business properties) in a table in any of the MicroStation supported relational databases such as Oracle, Microsoft Access, SQL Server etc... Please refer to the MicroStation help files for additional information.

This ability relate business properties (e.g. database attributes) to centroids, boundaries and/or shapes can be useful when creating and/or maintaining data for use in spatial or thematic analysis.

Regards,

Jeff Bielefeld [Bentley]