Mondrian | Parent Child Hierarchy is not working properly - parent-child

Question

I have created a dimension with parent-child hierarchy as follows -
<Dimension type="StandardDimension" visible="true" foreignKey="ContextID"
highCardinality="false" name="Learning Context">
<Hierarchy name="Learning Context Level" allMemberName="All Contexts"
hasAll="true" primaryKey="ID">
<Table name="LearningContext">
</Table>
<Level name="ID" visible="true" column="ID" type="Numeric"
uniqueMembers="true" levelType="Regular" hideMemberIf="Never"
parentColumn="ParentID">
</Level>
</Hierarchy>
</Dimension>
The problem is, when i want to get the children of a child, then i have to put it's parents as well in the mdx query.
For example -: I have a row with id 5, whose children i want to see.
Now my mdx query is..
select
Descendants([Learning Context.Learning Context Level].&[5],
[Learning Context.Learning Context Level].[ID], SELF_AND_AFTER) on 0
from
StudentActivity
which says :
Mondrian Error:MDX object '[Learning Context.Learning Context Level].&[5]' not
found in cube 'StudentActivity'
But when i execute following query... it works fine.
select
Descendants([Learning Context.Learning Context Level].&[1].&[2].&[3].&[5],
[Learning Context.Learning Context Level].[ID], SELF_AND_AFTER) on 0
from
StudentActivity
I do not want to use all the parents of a child to get its children.
Please help me out.

Answer 1

If you use a parent-child hierarchie, you have to prepare and use a closure-table