The original data table
| title | publisher | year | author1 | author2 | author3 |
| "Elaborate PHP" | Electronic Industry Press | 2009 | Galla peak | ||
| "Elaborate JavaScript" | Tsinghua University Press | 2013 | Galla peak | Ying Xin | |
| "Highly concurrent web site" | Electronic Industry Press | 2014 | Li Wenkai | Zhang Tao | Li strong |
| "LAMP" Band of Brothers | Beijing Normal University Press | 2015 | Li Chao | Li Ming |
The first paradigm:
(1) similar content data must be eliminated ( "elimination" approach is to create a data table to store them)
Create a data table (2) must be for each group of related data
(3) each data table a record must be progressively identified
Book Database: First Normal Form
| id | title | publisher | year | author |
| 1 | "Elaborate PHP" | Electronic Industry Press | 2009 | Galla peak |
| 2 | "Elaborate JavaScript" | Tsinghua University Press | 2013 | Galla peak |
| 3 | "Elaborate JavaScript" | Tsinghua University Press | 2013 | Ying Xin |
| 4 | "Highly concurrent web site" | Electronic Industry Press | 2014 | Li Wenkai |
| 5 | "Highly concurrent web site" | Electronic Industry Press | 2014 | Zhang Tao |
| 6 | "Highly concurrent web site" | Electronic Industry Press | 2014 | Li strong |
| 7 | "LAMP" Band of Brothers | Beijing Normal University Press | 2015 | Li Chao |
| 8 | "LAMP" Band of Brothers | Beijing Normal University Press | 2015 | Li Ming |
Second Normal Form:
(1) As long as the contents of the column data duplication, it means that the data should be split into multiple sub-table table
(2) must be resolved in the form of a data table associated with the foreign key
titles data sheets: a second Paradigm
| titleid | title | publisher | year |
| 1 | "Elaborate PHP" | Electronic Industry Press | 2009 |
| 2 | "Elaborate JavaScript" | Tsinghua University Press | 2013 |
| 3 | "Highly concurrent web site" | Electronic Industry Press | 2014 |
| 4 | "LAMP" Band of Brothers | Beijing Normal University Press | 2015 |
Data Sheet authors: second Paradigm
| authorid | author |
| 1 | Galla peak |
| 2 | Ying Xin |
| 3 | Li Wenkai |
| 4 | Zhang Tao |
| 5 | Li strong |
| 6 | Li Chao |
| 7 | Li Ming |
rel_title_author Table: second Paradigm
| titleid | authorid |
| 1 | 1 |
| 2 | 1 |
| 2 | 2 |
| 3 | 3 |
| 3 | 4 |
| 3 | 5 |
| 4 | 6 |
| 4 | 7 |
Third Normal Form:
(1) data column not directly related to the primary key must be eliminated ( "elimination" approach is to re-create a table to store them)
titles Datasheet: third paradigm
| titleid | title | publisherid | year |
| 1 | "Elaborate PHP" | 1 | 2009 |
| 2 | "Elaborate JavaScript" | 2 | 2013 |
| 3 | "High concurrency Web site." | 1 | 2014 |
| 4 | "LAMP Band of Brothers" | 3 | 2015 |
publishers Datasheet: third paradigm
| publisherid | publisher |
| 1 | Electronic Industry Press |
| 2 | Tsinghua University Press |
| 3 | Beijing Normal University Press |