Lecture 2 - Database Terminologies



In order for us to understand what is the database we need to understand it a bit more. Lets’ understand the basic terminologies of the databases.

Basic Database Terminologies


Cell


The intersection of a row and column is called a cell/field or data item

AdmNo
Name
Father’s Name
Class
Address
Phone
13056
M. Zulqarnain
M. Anar
XII
New Sadiq Lines
052-1234567
13001
Ibrar Zeb
Jehanzeb Khan
XII
Sadiq Lines
052-9784661
12096
M. Waqas Latif
M. Latif
XII
Narrowal
052-7841561
50179
M. Faheem Ahsan
M. Ahsan
XI
HQ 15 Div
052-1341313
50017
M. Rizwan
M. Ramzan
XI
Dalowali
052-1234568
10996
Rana Ubaid Ashraf
M. Ashraf
XI
Askari 2
052-3434311
50165
Hasnain Mehdi
Shafaqat Hussain
XI
Sublime Chowk
052-1234567
50164
Naqi Abbas
Shafaqat Hussain
XI
Sublime Chowk
052-1234567

Table 2 – Cells/Field or Data Item Elaborated

Shaded cells are called cell/field or data item

Row


Horizontal collection of cells is called a row/record or tuple

AdmNo
Name
Father’s Name
Class
Address
Phone
13056
M. Zulqarnain
M. Anar
XII
New Sadiq Lines
052-1234567
13001
Ibrar Zeb
Jehanzeb Khan
XII
Sadiq Lines
052-9784661
12096
M. Waqas Latif
M. Latif
XII
Narrowal
052-7841561
50179
M. Faheem Ahsan
M. Ahsan
XI
HQ 15 Div
052-1341313
50017
M. Rizwan
M. Ramzan
XI
Dalowali
052-1234568
10996
Rana Ubaid Ashraf
M. Ashraf
XI
Askari 2
052-3434311
50165
Hasnain Mehdi
Shafaqat Hussain
XI
Sublime Chowk
052-1234567
50164
Naqi Abbas
Shafaqat Hussain
XI
Sublime Chowk
052-1234567

Table 3 - Rows/Record or Tuple Elaborated

Shaded rows are called row/record or tuple

Column


Vertical collection of cells is called a column/property or an attribute.

AdmNo
Name
Father’s Name
Class
Address
Phone
13056
M. Zulqarnain
M. Anar
XII
New Sadiq Lines
052-1234567
13001
Ibrar Zeb
Jehanzeb Khan
XII
Sadiq Lines
052-9784661
12096
M. Waqas Latif
M. Latif
XII
Narrowal
052-7841561
50179
M. Faheem Ahsan
M. Ahsan
XI
HQ 15 Div
052-1341313
50017
M. Rizwan
M. Ramzan
XI
Dalowali
052-1234568
10996
Rana Ubaid Ashraf
M. Ashraf
XI
Askari 2
052-3434311
50165
Hasnain Mehdi
Shafaqat Hussain
XI
Sublime Chowk
052-1234567
50164
Naqi Abbas
Shafaqat Hussain
XI
Sublime Chowk
052-1234567

Table 4 - Column/Property or Attribute Elaborated

Shaded rows are called row/record or tuple

Relation


Collection of rows and column is called a relation or a table.

AdmNo
Name
Father’s Name
Class
Address
Phone
13056
M. Zulqarnain
M. Anar
XII
New Sadiq Lines
052-1234567
13001
Ibrar Zeb
Jehanzeb Khan
XII
Sadiq Lines
052-9784661
12096
M. Waqas Latif
M. Latif
XII
Narrowal
052-7841561
50179
M. Faheem Ahsan
M. Ahsan
XI
HQ 15 Div
052-1341313
50017
M. Rizwan
M. Ramzan
XI
Dalowali
052-1234568
10996
Rana Ubaid Ashraf
M. Ashraf
XI
Askari 2
052-3434311
50165
Hasnain Mehdi
Shafaqat Hussain
XI
Sublime Chowk
052-1234567
50164
Naqi Abbas
Shafaqat Hussain
XI
Sublime Chowk
052-1234567

Table 5 - A Relation or Table

As you can see that the data is organized in a table, which is easy for us to understand. We can have multiple tables in a database.

 

How can we identify a particular tuple in above table?

What is/are the criterion for uniquely identifying a record?

What two attributes can be used to tell which students are siblings?
Here comes the concept of a KEY. It is a yardstick which would enable us to extract, sort or create relationships.
Location: Siālkot, Pakistan

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