ust getting started with databases? Here's a rundown of
the top things that I wish I knew before I got started in the field.
These facts are guaranteed to make your life easier!
You
can't avoid it. The Structured Query Language forms the core of all
relational databases. It provides a uniform interface to Oracle, SQL
Server, Access and other relational databases and is a "must learn" for
all aspiring database users. In fact, I encourage you to take an
introductory SQL course before you even attempt to learn any specific
database software. The investment of time will help you build a proper
foundation and get started in the world of databases on the correct
foot. For a quick start, read
SQL Basics or, for a more comprehensive introduction, take our
free Learning SQL e-course.
More Info
The
selection of a primary key is one of the most critical decisions you’ll
make in the design of a new database. The most important constraint is
that you must ensure that the selected key is unique. If it’s possible
that two records (past, present, or future) may share the same value for
an attribute, it’s a poor choice for a primary key. When evaluating
this constraint, you should think creatively. You'll also need to avoid
sensitive values, such as Social Security Numbers, as they raise privacy
concerns. For more information on selecting a strong primary key, read
Choosing a Primary Key.
NULL
is a very special value in the world of databases, but it's something
that beginners often get confused about. When you see a NULL value,
interpret it as "unknown". If a quantity is NULL, that doesn't
necessarily mean that the quantity is zero. Similarly, if a text field
holds a NULL value, that doesn't mean that there isn't an appropriate
value, it's simply unknown. For example, consider a database containing
information about children who attend a particular school. If the
secretary entering the record does not know a student's age a NULL value
is used to indicate the "unknown" placeholder. The student certainly
has an age, it's just not present in the database.
If
you already have tons of data stored in Excel (or other) spreadsheets,
you can save yourself mountains of time by converting those spreadsheets
into database tables. Read our tutorial on
Converting Excel Spreadsheets to Access Databases to get started.
There
are many different databases out there and all offer a variety of
different features at different price points. Some are full-featured
enterprise databases designed to host huge data warehouses serving
multinational enterprises. Others are desktop databases better suited to
tracking inventory for a small store with one or two users. Your
business requirements will dictate the appropriate database platform for
your needs. Read our article
Database Software Options for more information.
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