QlikView Reference Manual.pdf - QlikCommunity - QlikView

to transform an adjacent nodes table to an expanded nodes table. See Hierarchy (page 236) for more information.
A problem with the expanded nodes table is that it is not easy to use the level fields for searches or selections,
since a prior knowledge is needed about which level to search or select in. The ancestors table is a different
representation that solves this problem. This representation is also called a bridge table.
The ancestors table contains one record for every child-ancestor relation found in the data. It contains keys
and names for the children as well as for the ancestors. I.e. every record describes which node a specific node
belongs to. The hierarchybelongsto keyword can be used in the QlikView script to transform an adjacent
nodes table to an ancestors table. See Hierarchy Parameters (page 214) for more information.
A good QlikView solution for a hierarchy needs both an expanded nodes table and an ancestors table. The
former is needed to create pivot tables and generally describe the nodes; the latter to allow selection of
entire trees. The two are linked through the node key, e.g. NodeID, which also links to a possible transaction
table.
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