Relational databases and structured query language (SQL)

aqa computing gcse

what is a primary key ?

a unique piece of data within a table to identify a record

what is a record

a collection of information linked together

what is a foreign key

a refrence to a primary key within another table

what is a table

a collection of related data

What is the purpose of the FROM structure in SQL?

to define which tables will be used

what is a field

a single type of information within a database

What is one disadvantage of storing data in a single table?

possibility of data inconsitency

what is redudancy

the duplication of data within a database.

What is the purpose of the SELECT structure in SQL?

to define which fields will be returned

what is delete used for

used to remove a record from a database table

what is a relational database

has multiple tables linked together by primary and foreign keys.

What is the purpose of the WHERE structure in SQL?

to define the criteria of the records returned

what is a data base

a persistent store of related information.