« First 3 Rules of Data Normalization for Newbies - Part 3First 3 Rules of Data Normalization for Newbies - Part 1 »

First 3 Rules of Data Normalization for Newbies - Part 2

12/20/04 | by Clarise | Categories: Modeling

In yesterday's blog, I discussed 1NF. Today, as promised, is the blog about 2NF.

The 2NF Rule states: "An attribute must depend upon its entity's entire UID". This basically means that every one of the attributes is functionally dependent on the whole key. Also, implicit to this rule is the fact that the entitiy is in its 1NF. So, if you have forgotten what 1NF is all about, review yesterday's blog. &#59;D

Consider the following example:

The attribute Warehouse_Location is not functionally dependent on Emp_ID. To make this Entity Relationship Diagram in 2NF, move the attribute Warehouse_Location to the entity Warehouse. To be compliant with the 1NF, Warehouse_Location is put in its basic form as Warehouse_Address1, Warehouse_City, Warehouse_State, Warehouse_ZIPCode.

This will result in:

Tomorrow's blog is the last installment of this series on the First 3 Rules of Normalization.

Send feedback »

No feedback yet

December 2019
Mon Tue Wed Thu Fri Sat Sun
2 3 4 5 6 7 8
9 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
30 31          
 << <   > >>
This blog contains thoughts that range from non-technical to technical. Its name is derived from "Yakity Blah Blah" a column I once had that discussed a cornucopia of ideas. Who am I? I'm Clarise Z. Doval Santos, providing Project Management and Technical Leadership for data management and analytic, data science, IoT and sensor analytics ecosystems 37.652951177164 -122.490877706959


  XML Feeds