Databases Flashcards
What is a database
A database is an organized collection of data
What is a field
A field is a single item of data (vertical, column)
What is a table
A set of data elements that are organized in rows and columns
What is a record
A record is a collection of related fields (horizontal, row)
What is a key field
A key field uniquely identifies each record in the database
What is a boolean expression
A boolean expression is a logical expression that produces a true or false answer
What are the boolean operators
The boolean operators are AND, OR, NOT
What are redundant data
Redundant data are duplicated data that are stored more than once in a database
What is verification
Verification is the process of checking if the data in the database matches the data as they were originally captured
What is validation?
Validation it a set of automatic checks which the computer conducts to ensure that the data in a database are valid
What are different validation checks
Existence: Checks if the data entered exist in the database
Format: Checks if the correct format has been used
Length: Checks that the text is less than a given number
Presence: Checks if the required information has been entered
Range: Checks that a number falls in the correct range
Type: Checks if the data entered is of the correct type
