Databases Flashcards
What is Data Validation
Ensures that the data entered by the user is of a sensible nature/reasonable/valid
Types of Data Validation
Data Type Check
Length Check
Range Check
Format Check
Presence Check
Explain Range Check
Ensures data is in a specific range
Has a upper and lower limit
Example of Range Check
A Persons month of birth should be in the range
1 Jan to 12 Dec
(lower limit) (Upper Limit)
Explain Presence Check
Ensures data is present or not null
Explain Data Type Check
Ensures Data is the correct data type
Explain Format Check
Ensures data matches a pre-determined pattern
E.g postcode
Explain Length Check
Ensures Correct number of characters are entered
What is a table
A table consists of a number of records
What is a record
A record is represented as a row in table
What is a field?
A field is a part of a record that stores a single data item represented by a column
What is a key field
A key field uniquely identifies one record
What is a Query
A query searches and filters data in the database and satisfies the query criteria
What are Forms?
Forms are used to collect data to create a new record, modify an existing record or view records already stored in a table
What are Reports
Reports are used to present results from queries in an effective manner
What are Macros
A small program written to perform a repetitive task automatically
What are Database Relationships
Database relationships link two or more tables in a database using a relationship type
What are the different types of relationships
One to One
One to Many
Many to Many
What is a foreign key
The key field in one table is stored in another table’s non key field
What is Big Data
Big Data refers to large amounts of data that have potential to be mined for information
Explain Volume
Refers to the amount of data stored by organisations and how old computers wouldn’t be able to process it
Measured in Terabytes
Explain Variety
Refers to the different types and varieties of data and can be stored in many formats such as video and audio not just text
Explain Velocity
Refers to a speed in at which data can be processed
Due to large volumes of data, there is a need to use more powerful computers to process the data more quickly
Explain Data Analytics
Data analytics involves analysing large volumes of data to produce useful information
Benificial for organisations to make descisions
