Data Flashcards
What does RAD stand for?
Rapid Application Development
What does RDBMS stand for?
Relational Database Management System
Tables, fields, & relationships are called base elements or….
Schema
FM field data types (5): T N D T T
Text Number Date Time Timestamp
A coherent, distinct type of thing the app will track (think nouns of a system description)
Entity
A quality or feature regarded as a characteristic or inherent part of someone or something
Attribute
Spreadsheet Term: Worksheet … data modeling term?
Data Modeling Term: Entity
Data Modeling Term: Entity … Database term?
Database Term: Table
SS Term: Worksheet - DM Term: Entity … Database term?
Database Term: Table
SS Term: Column … DM Term?
Data Modeling Term: Attribute
SS Term: Column - DM Term: Attribute … Database Term?
Database Term: Field
SS Term: Row … Data modeling term?
Data modeling term: Individual instance of this entity
SS Term: Row - DM Term: Individual instance of this entity … Database Term?
Database Term: Record
A collection of data categories (entities) that have been connected in various ways.
Relational database
Connections between data categories
Relationships
Customer - Order Relationshp
Each order is associated with one and only one customer.
Each customer may potentially have many orders in the app.
One-to-many relationship
Actor - Movie Relationship
One actor may act (over time) in many movies.
One movie generally has roles for many actors.
Many-to-many relationship
A diagram that shows a number of entities and their relationships.
Entity-Relationship Diagram (ERD)
An attribute that is guaranteed to be non-empty, unchanging, and unique for each occurrence of a given entity.
Primary Key
An attribute used to establish a link to another entity, generally by pointing back to the primary key of that entity.
Foreign Key
When a field has more than one value at once…
Multivalued attribute
How to resolve a many-to-many relationship
Two one-to-many relationships with a ‘join entity’ with 2 foreign keys. Each foreign key is the primary key from the main entities. Add any other additional attributes (if needed)
—–|< (hatch plus fork)
Minimum of one, maximum of many
—–o< (circle plus fork)
Minimum of zero, maximum of many
