Database ensign and development Flashcards
What is a functional requirement
The tasks that the database should be able to perform and the data it should be able to hold
What is an end-user requirement
What the user needs to be able to do with the database
What is the data protection act designed to do
To ensure that personal dat is held securely and not shared with third-parties
Due to the data protection act what are the 4 things that businesses storing personal data must ensure
They have consent of the data subject to store personal information, the data is accurate and up to date, the data is used for the limited and specifically stated purposes and that the data kept safe and secure
What is an entity
A place where information about a person thing or concept is kept
What is an attribute
It describes the facts details and characteristics of an entity
What is the primary key
The primary key uniquely identifies each record in a table
What is the foreign key
The foreign key links one table to the other usually one fo the foreign keys is a primary key in one table
What is a data dictionary
Includes the name and description of the attributes and entities in each table
What is a text attribute
A combination of letters and numbers
What is a number attribute
Whole numbers and decimal places
What is a date attribute
Usually in the format DD/MM/YYYY
What is a time attribute
Usually in the format 00:00 but can be in the format 00:00:00
What is a Boolean attribute
True or false
What does a validation do
Ensure data is allowable and sensible, makes it harder to make mistakes
What does a range validation do
Ensures data is between a lower and upper limit
What does a restricted choice validation do
Limits the uer to a list of options
What does length check validation do
Restricts the number of characters that can be entered
What does a presence check validation do
Ensures that the field is not elect blank
What does referential integrity do
Ensures that the foreign key has a matching value in the corresponding primary key
What does SQL stand for
Standard query language
What is SQL used for
To interrogate the data held in the database
What is SELECT FROM used for
To select data from the database
What is WHERE used for
To ensure the only records that meet a specific condition are returned
What is ORDER BY used for
To order the results in ascending or descending order
What is INSERT INTO used for
To add a record to a table
What is UPDATE used for
To update a record currently held in the database. The WHERE identifies the record
What is the DELETE used for
To delete a recorder from the database. No WHERE means all content will be deleted from this table
What is the EQUI-JOIN used for
To display results form two different tables requires primary key and foreign key to be linked
What is the operator AND used for
Ensures that both conditions must be true
What does the operator OR do
Ensures that either condition must be true
What does the operator < mean
Less than
What does the operator > mean
More than
