Databases Flashcards
Data
Raw facts and figures
Ways of using databases
1) Search engines 2) Telephone directories 3) Online shop database 4) Information about student 5) Record of each book in library
Give advantages of databases? (7)
1) Can be sorted 2) Search 3) Filtered 4) Sharing 5) Validation 6) Backup 7) Saves space
Table
A structure in which data is stored in a database
Flat file database
A database whose records are stored in a single table
Record
A collection of data about single item
Field
One piece of data about an item
Data type
The format of data in a field
List data types (5)
1) Text 2) Integer 3) Real (number) 4) Date/time 5) Boolean
What is a Boolean
Data which has only two possible values
Give an example of a Boolean
Yes/No or True/False
Primary key
A unique identifier for each record in a database
Index
A list of values or items
Relational database
A database that has several tables linked by primary key fields
Foreign key
A primary key that appears in another table in a relational database
Where can a relational database be used?
In a veterinary clinic
I have a pet ID, Owner ID, Appointment ID, what are going to be linked?
Pet and Owner + Appointment and Pet
Give an advantage of a relational database
Data has to be entered only once
Develop the advantage of relation database that data has to be entered only once
Data doesn’t have to be reentered if the owner has several pets –> entering the data once reduces the chance of an error –> Error has to be corrected only once
Query
A method of searching a database
SQL
A specialized programming language for maintaining databases and generating queries
Query-by-example
A method of searching a database by stating the criteria to be searched
What does SQL stand for?
Structured Query Language
What is data validation
Making sure the user entered the right data
What doesn’t data validation insure?
That data is correct
How does the computer know that the data is valid?
It checks whether it matches the rules
