GetOrigCollectionKeys - Teradata Meta Data Services

Teradata Meta Data Services Programmer Guide

Product
Teradata Meta Data Services
Release Number
15.00
Language
English (United States)
Last Update
2018-09-28
Product Category
Teradata Tools and Utilities

GetOrigCollectionKeys

Purpose

The CMetaObject class GetOrigCollectionKeys function returns a list of CMetaObjectKeys that contains object ID and name of the origin class objects associated with this CMetaObject for the specified relationship.

The third variant of GetOrigCollectionKeys listed returns a list of CMetaRelationshipKey objects (contains object id, object name, class id, class name, and optional explanation text) which identify the collection of the destination class objects associated with this CMetaObject for the specified relationship. This API functions in all respects the same as GetOrigCollectionKeys3 except for the type of the return objects.

Description

The GetOrigCollectionKeys function is expected to be used by an application to enable it to display the name or ID of objects in a collection without having to read the entire collection of objects into memory. This is important for large collections which consume a large amount of process space if all objects are read into memory.

When the origin class supports versioning, GetOrigCollectionKeys will return the keys of object versions in the origin class that have a rigid relationship to the current version of this CMetaObject. The returned keys are not guaranteed to be for the current version of their respective objects, i.e CMetaPersist::IsPublished() may be true or false for each returned object key.

The relationship ID is be specified by the GUID relationship ID or the internal relationship ID (one must be set).

If the origin class of the relationship is a superclass, this function will only return objects in the origin class. To return objects in the subclasses, use the GetOrigCollection3 function.

Requirements

The internal object id must be set in the object and it must be for a version of the object. The ObjectID must be of an object in the destination class of the specified relationship.

The relationship id is specified by the GUID relationship id or internal relationship id (one of which must be set). CMetaObject must be an object in the origin class of the relationship.

The propFilter list may contain zero or more CMetaFilterInfo objects.

The PropertyID (SetPropertyID()) or PropertyName (SetName()) of the value attribute in each CMetaFilterInfo object must contain a valid Relative Property Id or name of a property description in the class.

The value attribute in each CMetaFilterInfo object must also be set to the value on which the search will be made. This value must be of the same type as the property description. For example, if the search is to be made on Relative Property ID = 1 and Relative Property ID 1 is defined as an integer, Value must be set to an integer (SetInt()). If relative Property ID 1 is a string, Value must be set to a string (SetString()).

The default ComparisonOperator in each CMetaFilterInfo object is EQUAL and the default LogicalOperator is META_AND.

If the propFilter list contains zero objects, the function will perform a search by strObjName only. If strObjName is also NULL, the API will return all the objects in the collection.

If the propFilter list contains objects and strObjName is set, the logical operator between the properties and the name will the “AND”. To perform a search of a name “OR” a property, set strObjName to NULL and add a CMetaFilterInfo object to the propFilter list for a name search.

For more information on creating the propFilter for the search, see Chapter 8: “CMetaFilterInfo Class.”

For more information on building the strObjName parameter for a search, see “Name Search” on page 131.

For more information on the settings for allClasses and returnClass, see “Inheritance” on page 132.

Syntax

HRESULT GetOrigCollectionKeys(
vector<CMetaObjectKey> &objectKeyList, 
const GUID &gRelID, 
const OBJECTID_t lRelID = NULLLOID);
 
HRESULT GetOrigCollectionKeys(
vector<CMetaObjectKey> &objectKeyList, 
const GUID &gRelID,
const OBJECTID_t lRelID,
LPCTSTR strObjName,
const bool WithLock = false);
 
HRESULT GetOrigCollectionKeys(
Vector<CMetaRelationshipKey>& objectKeyList, 
const MetaFilterInfoVector &propFilter,
const GUID &gRelID, 
const OBJECTID_t lRelID = NULLLOID,
LPCTSTR strObjName = NULL
const bool WithLock = false);
const OBJECTID_t returnClass = NULLLOID,
const bool allClasses = false,
const bool skipValidation = false);
 

Argument

In/Out

Description

objectKeyList

In/Out

Reference to the list of keys that will hold the collection returned. The list is cleared before adding the return collection.

propFilter

In

List of FilterInfo objects containing the property id and value to use to perform the search

gRelID

In

Relationship ID.
Can be set to NULLGUID if lRelID is set.

lRelID

In
(Optional)

Relationship internal ID.
Optional, if gRelID is set.

strObjName

In

Specific name of object in the collection to be returned.

WithLock

In

WithLock=true keeps the Orig Collection table locked for WRITE. Use within an explicit transaction. Set WithLock to true when one of the Orig Collection objects will subsequently be updated within the transaction. This prevents deadlocks caused by Teradata promotional locks.

returnClass

In
(Optional)

If the allClasses parameter is = true, the returnClass parameter is ignored. If the allClasses parameter = false

  • If returnClass = 0, the origin class defined in the relationship is returned.
  • If the origin class in the relationship is a superclass, return class defines the class type of object keys to return (the superclass or one of its subclasses)
  • If the origin class in the relationship is not a superclass and return class specifies a classid other than the origin class, an error will be returned.
  • allClasses

    In
    (Optional)

    If the origin class in the relationship is a superclass, setting allClasses = true will return all class types (superclass and subclasses). If allClasses = false, the origin class returned is determined by the returnClass parameter. If allClasses = true and the origin class in the relationship is not a superclass, only objects of the origin class defined in the relationship are returned. If allClasses = true, the return list is sorted first by class.

    skipValidation

    In
    (Optional)

    The function validates that the id of the object is an object in the destination class (or subclass) of the relationship. If returnClass is specified, the function will validate that the returnClass is the origin class (or subclass) of the relationship. If skipValidation is true, this validation is not performed. If the validation is not performed and the validation would have returned an error, the function will return zero object keys in the ObjectList.