Databases and SQL Flashcards
What is a Database?
A Database is a persistent store of organised data. Persistence means that the data in the database will remain there until its deleted.
What is a Primary Key?
A unique identifier for each record.
What is a Record?
Record Data for an object, person or place.
What is a Field?
Field Categories for each piece of data.
What is a Table?
A collection of records for a specific theme.
What is Data Redundancy?
Data Redundancy is where data is repeated in a database table.
What is Data inconsistency?
Leads on from Data Redundancy.
What is a relational database?
What is a relational database
Digital database based on the relational model of data
Why can data redundancy be a problem?
Makes the file larger than it needs to be
Why can data inconsistency be a problem?
More data there is the more likely there is an error
Explain the purpose of a foreign key
Something that links the primary key to the table.
Why might the primary key for one table, not be the same primary key in another table?
A table can only have one primary key
