From the course: Programming Foundations: Databases

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First normal form

First normal form

From the course: Programming Foundations: Databases

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First normal form

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- First normal form requires that values in each cell are atomic, and that tables have no repeating groups. This means that each field in each table has only one value in it, and that there are no columns representing repeated kinds of data for each row. First normal form is often extended to include the idea that there aren't duplicate rows in a table. This also suggests that the order of rows and columns is not important to the data. The primary tables that we're using already satisfy first normal form. But let's take a look at ways we might have built these tables that don't satisfy it. In this first example, we've extended the customer's table with three columns for favored dishes. But these are repeating groups, and this violates first normal form. Another approach might have been to put all the keys for dishes in a list in one cell. This is also a repeating group, and so it violates first normal form, as…

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