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Expands into an autoJoinTables operator.
Syntax
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LQL
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@autoJoinTables(parent: TableReference, children: TableReferenceList, [result: TableResultList]) |
If result is omitted, the value parent +: children is used.
Examples
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LQL
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@autoJoinTables(P, [C1, C2, C3]) # equivalent to @autoJoinTables(P, [C1, C2, C3], [P, C1, C2, C3]) |
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@autoJoinTables(P, [C1, C2, C3], [P, C2]) |
Semantic
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The macro expands to autoJoinTables(joinTables, result), where joinTables is the distinct concatenation of reverseDfsOrder(parent, child) for every child table in children, and reverseDfsOrder(p, c) is the reverse of the DFS ordering obtained by traversing the inverted subdag between p and c starting from c.
In other words, joinTables is the set of all nodes on every path between a child and the parent node, ordered in a specific way to make autoJoinTables work.
Use case
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Suppose you have tables similar to
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