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For example: Suppose an agriculture-based company wants to store its employees’
names and contact details. It creates a table as presented in Table 8.8.

Table 8.8: An example of a table not conforming to 1NF

emp_id emp_name emp_address emp_mobile Chapter Eight: Databases and Database Management Systems
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101 Hamis Waya Iringa 0658000770

102 Erick Misitu Mbeya 0713876776;
0767000771
103 Mwantumu Chake Coastal 0688000775
104 Namdori Mchicha Arusha 028675432;
0736000671

As you can see from Table 8.9, employees (Erick and Namdori) have two mobile
numbers, so the company stored them in the same field as you can see in emp-
mobile. Therefore, this table is not in 1NF as a rule says, “each attribute of a table
must have atomic (single) values”; the emp_mobile values for employees Erick and
Namdori violate this rule. To make the table comply with 1NF, we should have those
anomalies fixed in the data, as indicated in Table 8.9.

Table 8.9: An example of a table conforming to the First Norm Form (1NF).

emp_id emp_name emp_address emp_mobile
101 Hamis Waya Iringa 0658000770
102 Erick Misitu Mbeya 0713876776
102 Erick Misitu Mbeya 0767000771
103 Mwantumu Chake Coastal 0688000775
104 Namdori Mchicha Arusha 028675432
104 Namdori Mchicha Arusha 0736000671

For example, if we want to put Table 8.9 in the 1N, it will look as in Table 8.10

Table 8.10: The first normalized form
Full name Address Movie_industry Sports
Ismail Makame Kijichi Hollywood Football
Ismail Makame Kijichi Bollywood Basketball
Ismail Makame Kijichi Hollywood Basketball
Ismail Makame Kijichi Bollywood Football
Rehema Kiongwe Mnazi Moja Swahiliwood Netball

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Student’s Book Form Five

Computer Science Form 5.indd 461 23/07/2024 12:34