Database Interfaces

The database related interfaces are provided by the interface assemblies:

• Aveva.Pdms.Database.dll and PDMSFilters.dll

This interface has the following main classes:

Namespace: Aveva.Pdms.Database

• DatabaseService: The sole purpose of this class is to open a project.

• DbAttribute: The class has two purposes:

  • Instances of the class are used to identify and pass around attributes.

  • The methods allow the retrieval of metadata about an attribute. for example, type, size, Name, pseudo or not, The class is valid for system attributes and UDAs.

• DB: This class provides information on the opened DBs.

• DbElement: Instances of DbElement are used to identify an element. This is the main class for reading and writing to the database. The methods cover:

  • element creation

  • element deletion

  • copy

  • getting/setting attributes and rules

  • navigating the DB

  • evaluating database expressions.

• DbElementType: The class has two purposes:

  • Instances of the class are used to identify and pass around Element types.

  • The methods allow the retrieval of metadata about an Element type. for example, Name, description, allowed attributes and members .

The class is valid for system types and UDETs.

• DbEvents: This class contains the mechanisms for subscribing to database events. It covers savework, getwork, undo, redo, flush, refresh, drop events plus capturing general database changes.

• DbExpression: Class to hold a database expression. These are the same as PML1 expressions. Methods to evaluate expressions are on the DbElement class.

• DbPseudoAttribute: This Class allows pseudo attribute code to be plugged in for UDAs.

• DbRule: Class to hold a database rule

• DbUserChanges: This is passed through by the 'database change' event. It contains a list of database changes made since the last 'database change' event was raised. Changes may be queried down to the attribute level.

• MDB: Methods to do operations on an MDB. for example, savework, getwork.

• Table: Various classes to access the internal Dabacon tables. for example, the name table.

• Project: The main method is to open the MDB.

As well as the class methods there is a lot of functionality that can be accessed via pseudo attributes. The relevant pseudo attributes are listed where relevant.