In the most simplest of terms, a database is a piece of software used to store information.
The database program is responsible for ensuring that data, or information if you prefer, is stored correctly and accurately.
These applications can be very simple, or quite complex depending upon a variety of factors. Some of them run on a standard desktop or laptop computer, and are used by just one person, or a couple. Others databases are more complex and have a dedicated computer which runs a single database, and this database can be accessed by hundreds or even thousands of users at one time.
Regardless of its complexity, a database provides four main data related functions, often referred to as CRUD – Create, Read, Update, and Delete.
Create refers to the ability of the user to add new data to the database for storage. This could come from typing it in directly, using an external application which can send information to the database, or loading data from another location, for example and Excel file.
The most commonly used function is the read function. This is often referred to as querying the data. That’s basically a fancy way of saying that it allows you to ask a question from the data stored within the database.
Sometimes they query is simple, like “list all employees”. Other times it is more complex, such as “list all accounts who have purchased more than $5 million in the last 3 years, who live in Chicago, but haven’t purchased a specific product”. Of course, you can get even more complex than that.
Update means that some data stored in the database is no longer valid and needs to be changed. Consider your employee record at work. If you move to a new location, you will need to update your address so it is correct. This is much faster and easier than deleting all of your information and re-entering all of it again.
Finally, you will need to be able to delete some data. Most often we keep data, and just flag it as inactive. However, sometimes we want to permanently remove that data – that is what the delete functionality is for. Note that there is no recycle bin to undo that change.
There are two main types of databases, relational and non-relational, but regardless of type, they will work approximately the same.
Most databases will also provide a level of security. This means they will have a way to allow, or prevent, a user from performing one or more of those data functions on one more more data sources.
For example, the interns at a company might be able to add data relating to new customers, but couldn’t review existing customers. Full time employees however could look up a customer and update their information, in addition to adding a new customer. However, only the system admin would have the ability to remove a customer record. Your permissions would be assigned to you by the database administrator.
What is a Database? was originally found on Access 2 Learn
