What is a Database?

If you have always been wondering what a database really is and why it is used, then this article is for you! This article covers very basic details about a database and its usage. So read on to find out more.

So what exactly is a Database?

Let’s see what a database is with a very general example so that it starts making much more sense once we get to the actual technical explanation of the same. That said, do you recognize what the following is and what you may have used it for?

Post it Sticky Notes

Well, if you have guessed it that it’s a Post-It sticky notes, then you are correct! And what do you use it for? You use it to write notes. So if you have ever written something at least on a single sticky note and carried the entire sticky note pack in your pocket, then you “virtually” carried a “database” with you! Still unclear, read on for clarity!

Let’s assume that you just purchased a Sticky Notes pack. On the first page/note of the pack, you write down some of the items that you would like to purchase from a grocery store. In other words, you write a “checklist” of the items that you would like to purchase so that you can keep a “track” of items that you have already bought and pending buying. That said, lets assume that your checklist looks something like this and you have written all of this on the first note of the Sticky Notes pack:

STICKY NOTE 1:

  1. Cookies – 1 pack
  2. Body Wash – 3
  3. Jogging shoes – 1
  4. Pecan Pie – 1
  5. Toothbrush – 2
  6. Milk – 1 Gallon

As you would carry the above checklist, once you purchase an item, you would mark the item as checked to indicate that its purchased and you can move on to the other items that have not been purchased. All this helps in tracking the purchase and your overall experience, even better and more “organized“!

Having said that, the above checklist looks jumbled up, doesn’t it? There’s no proper order to it. Wouldn’t that be really nice to list all the items that are available under the same aisle, listed under the aisle name so that when we visit that aisle, we can grab all the items from that aisle without having to jumble our shopping across different aisles? Of course, it would be great! That said, let’s re-organize our list so that the items are listed under the aisle name. Let’s dedicate a sticky note for each of the aisles that we wish to shop from and then list the different items under each of that aisle.

STICKY NOTE 1/AISLE 1 – SNACKS

  1. Cookies – 1 pack

STICKY NOTE 2/AISLE 2 – FRESH PRODUCE

  1. Pecan Pie – 1
  2. Milk – 1 Gallon

STICKY NOTE 3/AISLE 3 – BODY CARE

  1. Body Wash – 3
  2. Toothbrush – 2

STICKY NOTE 4/AISLE 4 – FOOTWEAR

  1. Jogging shoes – 1

As can be seen from the above, the aisles are split up across 4 sticky notes and now its super easy for us to refer to the notes based on the aisle information written in it and then we will be able to purchase the items listed under that specific note/aisle and then mark it as purchased. This makes everything much more organized than before. Agreed? Then continue reading below.

So lets discuss this above situation now, in terms of a “Database“. The whole pack of sticky notes represent a “Database“. Each of the separate, organized sticky notes (with only a single aisle information and the products under just that specific aisle) represent a “Table” each. Each of the items listed in each of those sticky notes (read tables) are listed in “Rows” and with numbers in front of them, so that its easy for us to count the number of items in each aisle and keep a track of it. This number is called the “Index” and it helps us keep track of data. (We will read more about indexes in another post.) The row number, the name of the items that need to be purchased, the quantity that need to be purchased and the status of the purchase are listed in a “column” of their own. In summary, it would look like this:

TABLE 1 - SNACKS
--------------------------------------------------
ITEM NUMBER  | ITEM NAME |  QUANTITY  | PURCHASED
--------------------------------------------------
1.           | Cooies    |  1         | Yes
--------------------------------------------------

TABLE 2 - FRESH PRODUCE
--------------------------------------------------
ITEM NUMBER  | ITEM NAME |  QUANTITY  | PURCHASED
--------------------------------------------------
1.           | Milk      |  1         | Yes
--------------------------------------------------
2.           | Pecan Pie |  1         | No
--------------------------------------------------

From the above layout, “Item Number“, “Item Name” and “Purchased” represent the Columns of the Table. Each of these columns can only contain the specific type of data assigned for that purpose. For example, the columns Item Number and Quantity will only and always contain just numbers. The Item Name column and Purchased column contains string of text. So just as listing the above data in a Sticky Note would make it easy to refer and understand the content of the note, the data is listed in the table in the above format to make it easy for the system to store and retrieve data as needed.

All the basic information about the table and the type of data it is going to store is referred to as “Table Structure“.

Recap – What is a database?

So let’s quickly recap what a database is, what is used for and what it contains. A database is a data storage/container. It can contain a single table or multiple tables, based upon the needs of the application. Each Table contains multiple rows and columns. The table columns represent the field (read as Headings) that they are storing the information about and the rows of data that immediately follow the headings represent the actual data. This data is created, updated, edited and deleted as per the application users requests.

Conclusion

We have just seen what a database is at its core, how the information is stored in it and how a database makes life easy for us. In later posts, we will see how this data is read, what language is used, kinds of databases available and much more. Share your thoughts by leaving a comment below!

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