Topic 5 Part 2 Flashcards
Define a table:
A collection of records organised into rows and columns within a database.
Where can we find databases?
Websites (e.g., login systems)
Banking systems
Retail and inventory systems
What does an entity represent in a database?:
An object or concept with attributes, like a customer or product.
What is another term for field?:
Attribute
Define the term foreign key:
A field in one table that links to the primary key of another table to establish relationships.
By adding a primary key, what can we make sure?:
That each record in a table is unique.
Name all the entity relationships:
One-to-one
One-to-many
Many-to-many
Explain one-to-one,
One-to-one: One record in a table is linked to one record in another table.
Explain one-to-many
One-to-many: One record in a table is linked to multiple records in another table.
Explain many-to-many
Many-to-many: Records in one table are linked to multiple records in another, often using a bridge table.
Advantages of using a primary key:
- Ensures unique identification of records.
- Prevents duplication of data.
- Maintains data integrity.
- Simplifies relationships between tables.
Define the term data mining.
Data mining is the process of analysing large sets of data to discover patterns, relationships, or useful insights. It often uses techniques like machine learning, statistics, and database systems.
Where is data mining used?
Where it’s used:
Marketing: Identifying customer preferences for targeted advertising.
Healthcare: Finding trends in patient data to predict diseases.
Fraud detection: Spotting unusual patterns in financial transactions.
Retail: Predicting product demand based on past sales.
Data Extraction
Definition:
Data extraction involves retrieving specific data from a larger set, usually from databases, documents, or web sources. It prepares raw data for analysis or use in another system.
Where is data extraction used?
Where it’s used:
Data migration: Transferring data from old systems to new ones.
Web scraping: Collecting information from websites for analysis.
Document processing: Extracting names, addresses, or invoices from scanned files.
Composite Key
Definition:
A composite key is a combination of two or more fields (columns) in a table that together uniquely identify a record.
Example:
Imagine a table tracking students enrolled in courses.
Fields: Student_ID and Course_ID
Individually, neither Student_ID nor Course_ID is unique because students can take multiple courses. But together, Student_ID + Course_ID can form a unique composite key
Where do composite keys come in handy?
When no single field is sufficient to uniquely identify a record.
In many-to-many relationships (e.g., students enrolling in courses).
Database
Definition:
A database is an organised collection of data that allows for efficient storage, retrieval, and management. It typically consists of tables containing rows (records) and columns (fields).
Give examples of databases
Examples:
A banking database stores account information.
A library database tracks books, authors, and borrowers.
A retail database keeps inventory, sales, and customer data.
Foreign Key
Definition:
A foreign key is a field in one table that links to the primary key in another table. It establishes a relationship between two tables and ensures data integrity.
Example of a foreign key
Example:
Table 1: Customers
Customer_ID (Primary Key)
Table 2: Orders
Customer_ID (Foreign Key)
The foreign key ensures that each order is associated with a valid customer.
How can the information revealed from data extraction be valuable to an organisation?
The information that is revealed as a result of data extraction is very valuable to an organisation.
It can help inform lots of decisions such as:
* What their next product should be
* How to improve the sales of a current product
* What investments to make
* What services they could improve
* What the next technological advances could be
* How are they performing against their competitors
What are the benefits of having a primary key in a database?
- It helps prevent duplicate records being created in a database.
- It helps with upgrading or deleting a specific record.
- It helps set up relationship links between different tables in a database.
