Databases & SQL

Question 1

Define the term ‘Database’.

Answer 1

Database - A computerised system that makes it easy to search for, select and store information. Often used in places such as banks, schools, businesses, etc.

Question 2

Define ‘field’ and ‘record’.

Answer 2

Field - Categories for each piece of data in a table (Columns)

Records - Data for an object, person or place. (Rows)

Question 3

Define and Compare a ‘Primary Key’ and ‘Foreign key’.

Answer 3

A primary key is a unique identifier for records specific to that table whereas a foreign key is that but for another table that has been linked via it (linking field in the foreign table formed when making a relationship between them - becomes the primary key of the new table, by default).

Question 4

Describe a ‘flat-file Database’ and its problems.

Answer 4

Flat-file Database - Made up of only 1 table for everything which leads to problems such as data redundancy and data inconsistency.

Data Redundancy - Repeated data in a table, making the file unnecessarily large.

Data Inconsistency - If data is stored multiple times however it isn’t always the same, meaning the chance of errors occurring and data being inconsistent (hence the name) is higher

Question 5

What is a ‘Relational Database’?

Answer 5

Relational Database - Made up of more than 1 table, eliminating the problems of data redundancy/inconsistency; recognises relations between different tables

Question 6

What does SQL stand for?

Answer 6

Structured Query Language - Used to communicate/edited with databases