mysql - Grasping 3NF - Is this an indicator of a 3nf database? -


so, understanding, in 3nf database, primary key value can used determine every single other attribute in table.

  1. does mean foreign keys exclusively used create composite entities? how foreign keys fit in 3nf database?

what 'signs' database normalised? can tables in database normalised, while others not?

so, understanding, in 3nf database, primary key value can used determine every single other attribute in table.

not really. that's trivially true all normal forms. table in 3nf if it's in 2nf , there no transitive dependencies. strictly speaking, normal forms refer individual tables, not databases.

does mean foreign keys exclusively used create composite entities? how foreign keys fit in 3nf database?

no. can mix foreign key references , discrete values in way makes sense. or in ways make no sense.

what 'signs' database normalised?

the "signs" definitions of various normal forms. want know whether table "users" in 3nf? apply definition of 3nf it. if meets criteria, it's in 3nf.

can tables in database normalised, while others not?

since normal form (1nf, 2nf, 3nf, etc) characteristic of table, database might consist of tables in every possible combination of normal forms. might have tables in 2nf, in 3nf, in bcnf, in 6nf.


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