Database Design Techniques Flashcards
What is an Entity
IRL objects/concepts that will be stored in a DB
What is a Relation
It is a table that stores information about entities
What is a one-to-one relationship
a record on a table corresponds to one record in another table
what is a one-to-many relationship
a record in a table can be related to multiple records in a different table
what is a many-to-many relationship
multiple records in one table is related to multiple tables in an another table
what is a required value?
it ensures that a value cannot be NULL
what is a unique value?
it ensures that no two records have the same value for a specific attribute
what is a composite attribute?
attributes that can be divided into smaller parts
what is a multi-valued attribute
attributes that can have multiple values for a single entry
what is a controlled/ enumerated values?
predefined sets of values that an attribute can take.
what is a free-form value
any values are acceptable
what is a generalization
the extraction of common characteristics from multiple entities to a generalized entry
what is a specialization
a broad entity is divided into more specialized entities
Phone Number and Illnesses are considered what kind of attribute
Multi-Valued
An Address is what type of Attribute
Composite
