Cheat sheet of NFs of database

1st Normal Form Definition

A database is in first normal form if it satisfies the following conditions:

  1. Contains only atomic values
  2. There are no repeating groups

Unnormalized Table Example

1st Normal Form Example

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2nd Normal Form Definition

  1. It is in first normal form
  2. All non-key attributes are fully functional dependent on the primary key

Example Not In Second Normal Form

2nd Normal Form Example

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3rd Normal Form Definition

  1. It is in second normal form
  2. There is no transitive functional dependency

Example Not In Third Normal Form

3rd Normal Form Example

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posted @ 2015-03-19 15:23  wbzhang  阅读(305)  评论(0)  编辑  收藏  举报