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> I agree if you can use a recursive table Could you please elaborate on that? Which table will have recursive relation in this case?
by m33k44 7y ago
> I agree if you can use a recursive table
Could you please elaborate on that? Which table will have recursive relation in this case?
- sokoloff 7y agoCategory ID Category Name Category Parent ----------- ------------- --------------- 1 Animal NULL 2 Dog 1 3 Cat 1 4 Rabbit 1 5 Beagle 2 6 Lion 3 7 Tiger 3 8 Bengal Tiger 7 A Bengal Tiger (8) is a Tiger (7) is a Cat (3) is an Animal (1).
- protomyth 7y agojust for your sanity in a relational database alway put a root id for hierarchies. Also, you might want to skip the null and use a self reference depending on how you need to build the hierarchy. Root only matters if you have multiple hierarchies in a table.
- tracker1 7y ago+1 for root-id, this is a huge failing in a lot of threaded discussion table designs.
- protomyth 7y agoYeah, it really helps if you have to do some processing in the stored procedures and it helps with the query speed if properly indexed. I have seen folks put a level number in the table also, but that really depends on what the hierarchy represents.