Databases

Question 1

Define Database

Answer 1

A structured collection of data, allowing organized extraction of information

Question 2

What is a record?

Answer 2

A single row that contains all the information for a specific item or entity

Question 3

What is a primary key and what is its purpose?

Answer 3

a primary key is a unique identifier for each record in a table, which makes sure there are no duplicate entries

Question 4

Describe the difference between validation and verification

Answer 4

Validation checks if the right type of data is entered. Verification checks for exact data which matches the input

Question 5

What are the different data types and explain them

Answer 5

Real: Single floating-point number
Integer: Whole number
Character: Characters
Text: Groups of characters
Date: Date
Boolean: TRUE/FALSE or YES/NO

Question 6

What does SQL stand for and what is its primary focus?

Answer 6

Structured Query Language, Used for writing scripts and queries to retrieve information from a database.

Question 7

How can data be sorted in SQL queries?

Answer 7

(ORDER BY) clause, arranges results by a specified field either alphabetically or numerically.

Question 8

What does the wildcard (*) symbol do?

Answer 8

Selects all records from a specified table.

Question 9

What does the SELECT statement do in SQL

Answer 9

used to fetch specific fields in a database

Question 10

What is the difference between COUNT and SUM

Answer 10

COUNT is the number of records the meet the specific criteria, While SUM adds up all values in a specifies column.