First Normal Form (1NF)
What we saw in the solution for this situation is called the first normal form. Why? Because it adheres to the following four rules:
- Every column must be single-valued
- The data type of all the data in any column should be uniform
- Every column should have a unique name
- The order in which the records are ordered does not matter
As you can see, the column names in our tables are unique. Every column has only one data type (in our case, all the values are strings—even the employee IDs are strings). There are no multi-valued cells in the tables. The fourth one gives us the freedom to put the data in any order.
Remember the situation where Jon Doe owned 300 servers, and the server names were all jammed in a single cell? This is not allowed in the first normal form because it makes update operations difficult. The normal form helps prevent such situations.
Note
The first normal form is considered the least requirement for...
