Database View Elements and Attributes

LEXICON Command Reference Manual

Database Views : Database View Elements and Attributes

Database View Elements and Attributes

The hierarchy of Database View definitions is as follows:

* Hierarchy is not complete and is expanded elsewhere on the diagram

+ Definition is recursive


DBVWWL (Database View World)	is the top-level administrative element.
DBVWGR (Database View Group)	is used to group definitions into manageable administrative sets, this is for administration only and is not visible to users in other contexts.
DBVWSE (Database View Set)	is used to group Database Views for user presentation. These should contain related views as they are visible to the user. A Database View can be a member of a Database View Set even if it is not a direct member, refer to DBVW Attributes.
DBVW (Database View)	is a table definition that defines the display name, element criteria and columns.
ATTFIL (Attribute Filter)	elements define attribute constraints that limit the rows in the table. An attribute filter is a test executed against the selected element based on the value of a specified attribute such as DESC Equals Vessel. A database element must match all filters present in the Database View to be present in the resulting table.
EXPFIL (Expression Filter)	is an expression that must evaluate to TRUE or FALSE to determine whether a database element is part of the database view. A database element must match all filters present in the Database View to be present in the resulting table.
ATTCOL (Attribute Column)	elements define columns based on a single attribute. Attributes may be system attributes or UDAs. Qualifiers can be specified where required such as when accessing the status of a particular element (refer to ATTCOL Attributes). Columns based on attributes are by default editable but can be made to be read only to help with workflow management.
EXPCOL (Expression Column)	elements define columns based on a PML or XPATH expression. Expression columns are read only unless software is written to make them editable.
SRCELE (Source Element)	elements define a navigational step from the current context element to another database element. All columns defined in the Source Element are then based on the element that results from the navigation. Such columns are editable so rows in Database Views allow editing of more than one database element. Refer to Example Database Views for example uses of Source Elements.
CRERUL (Create Rules)	define the rules for element creation. If within a DBVW element then the rules permit row creation for the Database View provided that the AUTCRE attribute is set to TRUE. Information such as where to create the new item or what type of element to create can be fixed or specified using expressions. Refer to Data Sources to use parameters within expressions and how to prompt the user for information.
SETPAR (Set Parameter Rule)	elements are used to define parameters for expressions in other create rules. A parameter can be used in expressions on the CRERUL, SETATT or TESTEX elements. Parameters provide the ability to prompt a user for a single piece of information and then use it in multiple expressions.
SETATT (Set Attribute Rule)	rule defines a rule to set a database attribute when the element is created. This allows attributes to be defaulted at the point of creation of forces a user/application to provide a mandatory attribute value at the time of element creation.
SETSTA (Set Status Rule)	rules assign a status to the created item at the time of creation. This will help make sure all elements are being status managed.
TESTEX (Test Expression)	if this evaluates to true then the owning rule will be carried out, otherwise the owning rule is ignored.
COLREL (Column Relation)	elements define Parent/Child relationships between columns for application use. These relationships are currently not supported in the standard applications.

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