sqldatabasedatabase-designforeign-keys
Is it good practice to duplicate the connections to the grandparent in the parent and son in SQL?
I've seen different database designs in different projects. Some of them claim that from son to grandparent one should go through the parent (intuitively correct); in others there is a lot of duplication.
Which is right?
Solution
In the Son table, column ParentID also determines GreatParentID. This violates third normal form.
All else being equal, implementing normal form is a reasonable idea.
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