We’ve recently looked at ways to work with parent-child hierarchies, particularly in reporting scenarios. Regular parent-child hierarchies are great when working with dimensions that are ragged, but they have a critical limitation – any given node in the tree can only have a single parent node. A great solution to this problem is a DAG – directed acyclic graph.
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Accumulating values in a parent-child hierarchy
Last week, we looked at how to construct a visual representation of a hierarchy stored as a parent-child table. The obvious next step is to accumulate values stored on those nodes using this hierarchy.
An indented representation of a parent-child hierarchy
When you’re designing reports, they can often be based on hiearchies represented by “nodes” in a parent-child setup. To the end-user, the parent-child representation doesn’t provide very much readability, so you need to output this information in a human-readable form, for instance in a table where the names/titles are indented.
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