migration - Dependencies

This topic discusses the dependency API provided by the migration framework.

• A migration packet can have dependencies that are evaluated during migration to determine wheter the packet should run or not
• When the dependenciers are not met, the packet is marked as pending
  • The MinVersion and MaxVersion dependencies as well as the DBMSDependency will mark a packet as unnecessary instead

Classes

BaseDependency

The base class.

• All dependencies must subclass this class.

Methods

Function	Parameters	Return Value	Description
BaseDependency.__init__(self)			Initialize the dependency
BaseDependency.get_log_content(self)			Retrieve a list of all log statements in the buffer and clear it
BaseDependency.log(self, text)	text: String		Write to the internal log buffer

Properties

Property	Getter	Setter	Description
BaseDependency.is_met			This property is abstract and must be implemented in a subclass. It must return if the condition of the dependency is satisfied

DBMSDependency

Dependency on the type of database used.

Methods

Function	Parameters	Return Value	Description
DBMSDependency.__init__(self, expected_dbms)	expected_dbms: '000002' for Oracle and '000004' for MSSQL		Initialize the dependency

MaxVersionDependency

Dependency on Datenbank-Changeset

• Will check if the value in Datenbank-Changeset is greater or equal to the version this dependency was initialized with

Methods

Function	Parameters	Return Value	Description
MaxVersionDependency.__init__(self, version)	version: Customizing version like '39.5.11'		Initialize the dependency

MinVersionDependency

Dependency on Datenbank-Changeset

• Will check if the value in Datenbank-Changeset is less or equal to the version this dependency was initialized with

Methods

Function	Parameters	Return Value	Description
MinVersionDependency.__init__(self, version)	version: Customizing version like '39.5.11'		Initialize the dependency

PacketDependency

Methods

Function	Parameters	Return Value	Description
PacketDependency.__init__(self, packet_path, expected_state)	packet_path: Python-Pfad expected_state: PacketState		Initialize the dependency