databases and sql Flashcards
what is a database?
a database is a computerised system that makes it easy to select, search and store information.
what is a relational database?
a database made up of more than one table. Allows data to be separated and connected across several tables.
define table.
a collection of records for a specific theme.
define records.
A data structure that allows multiple data items to be stored in different fields.
define field.
categories for each piece of data in a table.
define primary key.
a unique identifier for each record.
define foreign key.
A primary key from one table that appears in another table to link the two together.
What is data inconsistency?
A situation where there are multiple tables within a database that deal with the same data but may receive it from different inputs.
What is data redundancy?
Data is repeated in a database table.
