Object Identifier (dbObject)

To access an object in the database, you must use a label known as the object identifier or ID. Each ID uniquely identifies a database object and is represented by the special type dbObject. Only database routines can create IDs, and you cannot alter IDs directly. When you use a function that operates on a database object, you must also give the ID as an argument to the function.

In programming terms, a variable of dbObject type represents the ID of an object in the database. If you delete the database object identified by a dbObject variable, that dbObject variable is invalid and cannot be used to do any database operation.

The delete and inter-cellview move commands in the Graphics Editor can destroy existing database objects and invalidate a dbObject ID. In addition, closing the last reference to a cellview (for example, closing the last Graphics Editor window the cellview is displayed in or directly calling dbClose or dbPurge) purges the cellview from virtual memory. This action makes obsolete all IDs of database objects stored in that cellview.

Related Topics

Data Stored as Objects