This week’s topic is focused on relational databases. The
required reading on Access Science discussed the inner workings of a good
database and introduced some of the basic terms. To expand my knowledge on
relation databases, I looked at an article titled ‘Introduction
to Relational Databases’. The article specifically discusses relational
databases. The second item I looked at is a video titled ‘What is a Relational
Database?’, which portrays a working example of a relational database.
The first article is an introduction to relational
databases, specifically with the use of MySQL. The purpose of the article is to
introduce the theoretical knowledge of databases so that a web developer does
not set themselves up for a future failure. To the author, a database is a “collection
of related files”. According to the article, there are also two types of models
for a database: hierarchical and network. The hierarchical model relates items
in a parent/child manner while network models relate items as owners/members.
As an example, the author develops a small relational database with poets and
poems. The poets and poems are separated into two different tables; however,
they are related by a common “Poet Code”. This is the idea behind relational
databases: tables are related by common keys. After developing the basic terms
and knowledge behind relational databases, the article continues to examine
common problems that occur in the initial database design, such as mismanaging
referential integrity. Referential integrity is defined as “a property of data
which, when satisfied, requires every value of one attribute (column) of a
relation (table) to exist as a value of another attribute in a different (or
the same) relation (table).” Overall, the article is a good starting point for
any novice database developer.
The video I watched is developed by Jason Roth, a senior
programming writer at Microsoft. The purpose of the video is to define a
relational database, with a working example. He begins by explaining why it is
better to make the switch from Microsoft Excel to a database software program,
such as SQL Server. He explains that, in Excel, it is quite easy to make a
mistake while editing multiple objects. In the video, Jason shows a basic
relational database and how it actually works. Instead of a single table, like
in excel, the tables are split up and are set to relate to one another without
the use of long codes. If a user tries to delete a value, the program will give
an error because the value is integral to a functional database. This is how
delete mistakes are avoided in relational databases. Relational databases also
allow the user to organize the data onto a website or create queries. Queries
are questions that can be answered using the relation database; this is useful
in finding specific values within a database.
No comments:
Post a Comment