.NET Customisation
User Guide
.NET Customisation
:
Database Interface
:
Data Model Definition Classes
: DbElementType
DbElementType
There is a single class for all element types.
The purpose of the class is to:
•
Instances of the class identify the element type. i.e. methods on other classes take a DbElementType as an argument rather than a string to denote an Element type. The DbElementType has 'value' semantics for comparison purposes. i.e. comparing of two DbElementTypes will always return true if they refer to the same type, even if they are different objects.
•
Access the metadata associated with element types.
External to the AVEVA module, the hash value can be used to uniquely identify an Element type. The hash value is a 32 bit integer.
Constructors
In C# a DbElementType object may be obtained in one of three ways:
1.
Use the globally defined instances in DbElementTypeInstance. This is the recommended and easiest way to obtain a DbElementType.
2.
The static 'GetElementType' method may be used to return a DbElementType given the Element Type name. This is only needed for UDETs. The colon must be included as part of the name.
3.
There is also a static 'GetElementType' method that may to be used to return a DbElementType given the hash value. This is only needed where a hash value has been stored outside of the AVEVA module.
4.
Various methods on other classes, such as DbElement will return a list of DbElementTypes.
Methods
The methods allow the Element type metadata to be accessed. For example:
•
Name
•
Description
•
BaseType (for UDETs)
•
List of attributes
•
List of UDAs
•
Allowed members
•
Allowed owners
•
Types that may appear above this element type
•
Types that may appear below this element type
•
Element types that may be referenced from a given attribute on this element type
•
Database types in which it occurs
Related ENUMS
DbNounManual- Manual category
DbType - DB type
Related Pseudo Attributes
Pseudo attributes that provide similar information on a particular element instance (i.e. on a DbElement) are:
Attribute Name
C# Data Type
Description
HLIS
DbElementType[]
List of all possible types in owning hierarchy
LIST
DbElementType[]
List of all possible member types
LLIS
DbElementType[]
List of all possible types in member hierarchy
OLIS
DbElementType[]
List of all possible owner types
REPTXT
String
Reporter text used for element type
ATTLIST
DbAttribute[]
List of all visible attributes for element
PSATTS
DbAttribute[]
List of pseudo attributes
UDALIS
DbAttribute[]
List of UDAs
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